The HobbitHouse Ilustrated Glossary of Woodworking terms
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back --- (1) The poorer quality side of the two wide surfaces of a plank or panel, as opposed to the face which is the better quality of the two. See plank.
back --- (2) The inward-directed wide surface of a plank or panel when it is in service.

back cut --- [noun] see felling cut
back cut --- [adj] synonymous with flat cut

background --- In wood carving, this is the area around the carving subject. In relief carving, this area is usually finely grooved or sanded, but it might be left plain.

backing board --- (1) A board put behind another board in a cutting operation such as sawing or routing so the the first board does not chip out when the blade moves out of it. The backing board provides support for the primary board and since the backing board is considered scrap, it doesn't matter if IT gets chipout.
backing board --- (2) The board remaining on the the faceplate of a veneer slicing machine after the veneer is all sliced off. These are usually thin boards, 1/2" to 3/4" thick, with mounting holes in them and they are discarded or go to scrap-wood operations.

backing grade --- Used to indicate cheaper veneers that are used on the back of a board or cabinet as opposed to the better quality veneers used on the front face.

backing off --- synonymous with undercutting

backing veneer --- Veneer that is too low in quality to use as face veneer and is used instead as backing for face veneer for added structural strength.

back lean --- A logging term referring to the condition where the weight of a tree is aligned opposite from the desired direction of felling. Back lean is NOT the opposite of head lean since if it is desired that a tree fall in the direction opposite of the head lean, then the head lead and the back lean are identical.

back saw --- A hand saw with a rectangular blade and a reinforcing rib, or spine, along the back for strength and stability. Types include razor saws, veneer saws, dovetail saws, and miter box saws. Back saws generally have fine teeth and are used for joinery cuts such as dovetails. Also see dozuki, which is the Japanese equivalent. Examples:



backsteady --- When turning long thin items, such as a spindle, on a lathe, there can be a tendency for the wood to flex. This can cause serious chatter which can make it impossible to obtain a smooth turning. Worse still, it can actually be dangerous since it is possible for such flexing to hit a resonant frequency and cause the wood to flip off of the lathe. A backsteady is any device that supports the wood so that it does not flex. Generally, it is some kind of roller system that supports the wood but that has wheels or rollers that move with the wood so that it doesn't cause wear. Also just called a "steady" and "steady rest". I assume from the name that there might have been versions at one time that just steadied a spindle from the back, but these days all the versions I see surround the spindle and support it with (generally) 3 rollers. There is a similar tool used for supporting the back of face turnings called a bowl steady. Example:



back surfacing --- The process of adding some kind of material added to the otherwise sticky back of shingles so that they don't stick to each other during storage prior to use.

balanced construction --- A construction such that the forces induced by uniformly distributed changes in moisture content will not cause warping. For example, the construction of plywood in which the grain direction of each ply is perpendicular to that of adjacent plies is balanced construction.

ball and claw --- see claw and ball

balloon calipers --- Transfer calipers with legs that are particularly widely rounded outward so that the calipers can fit over something considerably larger than the particular part of it being measured. These are used, for example, for measuring beads and coves on spindle turnings, but can also be used to measure the wall thickness of a hollow form. When there is a mirrored version of the measuring end, they are called double ended calipers. Examples:



ball pane hammer --- see ball peen hammer

ball peen hammer --- [also ball pane hammer] A hammer with one flat face and one globular face, used in various metal working operations. It is not a woodworking tool. The head is made of tough but relatively soft steel, which is good for working metal but not good for driving nails, so a ball peen hammer should not be used for nailing even though it has one flat head. Also known as an engineer's hammer, machinist's hammer, and mechanic's hammer. Examples:



ball screw --- A mechanical device for translating rotational motion to linear motion. It is just like a lead screw except that the sliding portion contains ball bearings and thus the device does not heat up quickly (the way a lead screw would) when used continuously in a powered situation.

baluster --- A spindle used as part of the support rail of a staircase. The balusters are topped by a banister. In residential buildings, these (the balusters and the banister, as well as the newels) are made of wood, but going up the external front of public buildings they are often all made of stone. Examples:



balustrade --- The protective barrier alongside a staircase or landing. This is normally composed of spindles that in this use are specifically called balusters and they are topped by a banister which is supported on each end by a newel.

banding --- (1) see edge banding
banding --- (2) A plain or patterned strip of veneer used to make decorative borders around the edge of a surface. First a shallow groove is routed into the surface and then the veneer is glued in place and the whole surface is sanded and finished.

band saw --- [also bandsaw] A saw that uses a continuous loop of flexible steel, with teeth on one side or both (usually only one, outside of saw mills), that runs on two or three wheels. Used in woodworking with narrow blades for cutting freehand shapes and with wider blades and a guide for resawing planks. Bandsaws come in sizes from a couple of feet high to monsters used in sawmills to cut up logs. Compare/contrast to table saw and see also bandsaw mill Examples:



bandsaw blade --- A long, continuous loop of flexible steel with teeth on one side, used as the cutting element of a bandsaw.

bandsaw mill --- A modern sawmill technology that uses a thinner band saw blade (less kerf therefore less sawdust waste than a circular saw). Such a bandsaw may have teeth on both edges of the blade, thus allowing cuts to be made in two directions instead of just one, improving efficiency and productivity.

band sawn --- Refers to a piece of lumber that was cut by a bandsaw and which therefore has straight saw tooth marks, perpendicular to the long dimension, on the face. Compare/contrast to circular sawn.

banister --- A handrail that runs along the top of the balusters of a staircase and is supported at both ends by newels. The term banister seems to be used synonymously with the term baluster sometimes, although I don't see why since they are quite distinct. Examples:



banjo --- The part on a lathe which slides along the bed and supports the tool rest. Illustrated with wood lathe.

bar --- The Long, thin projection plate of a chain saw, on which the saw chain travels. The far end of the bar is called the nose and improper use of the bar by way of attempting to cut starting with the nose can result in kickback. Examples:



bar auger --- A carpenter's tool for boring holes larger than those bored by a gimlet. Augers have a long shank with a cutting edge and a screw point and a handle fixed at 90 degrees to the top; that is, a standard wood auger is shaped like the letter "T". They have deep helical recesses that carry the shavings away from the bottom of the hole. Very large, powered versions of this tool (called "earth augers" or soil augers) are used to remove soil for fence posts and even large excavations. Examples:



bar clamp --- A type of clamp that uses a stiff metal bar to separate the jaws, one of which is fixed and the other of which has a screw mechanism to provide the clamping force. The force-providing head is able to move along the bar when the clamp is loose but is locked in place when the pressure starts to be applied. Also known as an "F clamp" because of the shape, these are generally a staple of any woodworking shop. The one disadvantage of a bar clamp is that they have a quite limited throat size; when a deeper throat is needed, a C clamp is called for. A similar, but larger, such device is the pipe clamp. Examples:



bark --- The outermost, protective, layer of a tree. The very inside of the bark, next to the cambium, is live (this is the phloem) and the outer bark is made up of dead cells. Bark will range in thickness from a fraction of an inch to many inches depending on the type and size of tree. I have heard of trees with bark a foot thick. See tree growth.

bark inclusion --- An isolated area in wood, largely made up of bark that has grown into the sapwood of a tree. This can be caused by irregular growth or due to damage to a tree. Bark inclusions are unsound and usually cause distortion of the surrounding wood grain(see irregular grain. The bark area is frequently completely overgrown over time by new growth and thus seems to exist magically inside the tree with no link to the outer bark. They are usually fairly shallow and are also called bark pockets. Some species, such a American black cherry, commonly have bark inclusion. Examples:

need to add bark inclusion pics


bark pocket --- synonymous with bark inclusion

barrel stave --- A curved plank used to make a barrel or keg. They are cooperage and in addition to liquid containers, they were also popular for the tops of sea chests. Pic below has staves, barrel, sea chest.



barrier coat --- A layer of finishing agent used to isolate layers either from each other or the from surface to which they are applied so as to increase adhesion, insure compatibility, or isolate contamination. Also known as a "tie coat".

bar stock --- Long cylinders of various cross section lengths of metal, usually round or square but could be rectangular, octagonal, or other. Although some definitions include hollow cylinders, I don't think that's correct; those should be called pipes or pipe stock. Examples:



basal area --- the cross-sectional area of the trunk of a tree taken at 4 1/2 feet above the ground; the sum of the basal areas of all the trees on one acre is used as a measure of forest density.

base --- The bottom or lowest part of or foundation of. In referring to a tree, it is that portion of the tree up to three feet above ground level.

baseboard --- [also called skirting, skirting board, and mopboard] A strip of molding a few inches high that covers and protects the joint between an interior wall surface and the floor. Examples:



base molding --- Molding put at the bottom of a wall to cover the joint between the wall and the floor. If the base molding doesn't fully cover the joint (due to a large amount of space left for expansion of wooden floors) an extra piece of molding, normally quarterround, is added at the bottom and this piece is called the base shoe.

base shoe --- Base molding sometimes doesn't quite cover the expansion space left at the edge of a wooden floor, so an extra piece of molding, normally quarterround molding, is added at the bottom of the base molding to cover the expansion space. When used in this way, the quarterround molding is called base shoe molding. Base shoe molding COULD be something other than quarterround but I can't recall ever having seen any other type used.

bast --- synonymous with phloem

bastard sawn --- synonymous with rift cut

batten --- A thin strip of solid material (usually wood). Battens are used for various purposes in building construction, as well as other various fields. Various definitions given in woodworking say that battens have a thickness that is "thin", "about 1/2 inch", "1/2 inch or less", "3/4 inches to 1 1/2 inches", and probably several other definitions, and that the width is "about 2 inches", "narrow or wide", "less than 3 inches", "1 to 3 inches", and probably several other definitions. Other definitions focus on the use rather than the size, and there also one finds numerous definitions, the most common of which are that battens are (1) used to cover vertical joints, (2) nailed on the back of two or more other boards to hold them together, and (3) thin planks to which panel materials, slates and roof tiles are nailed. See lumber sizes for other "sizes" of lumber.

battenboard --- synonymous with lumber core plywood

battery powered --- Refers to the large number of hand power tools that are available today in a version that runs off of a rechargeable battery instead of AC power. Just about all hand power tools today come in such versions. These are obviously much more portable than AC powered versions, but many of them suffer from lower power capabilities and/or only modest amounts of operating time before the battery needs recharging, however, battery technology continues to improve and therefore so do such tools.

baulk --- (1) A piece of square sawed or hewn timber of equal or nearly equal cross sectional dimensions. See lumber sizes for other "sizes" of lumber.
baulk --- (2) a rafter; one of several parallel sloping beams that support a roof

BDT --- Bone Dry Ton

bead --- (1) In lathe turning, a bead is a rounded projection, usually turned on a spindle although they are sometimes done on face turnings. There are specialty tools used for making them; see, for example, beading tool, beading and parting tool, and bedan. If the bead stands fully exposed above the surrounding wood, it is called a "standing bead" but if the surrounding wood is more or less flush with the top of the bead, then the bead is called an "inset bead". Often, it's not particularly meaningful to try to categorize a bead as inset or standing, but some cases are clearcut.
bead --- (2) A semi-circular piece of molding.
bead --- (3) A small rounded, raised profile, routed along the edge of a board, particularly the edges of boards that are placed vertically to form a wall paneling.

Examples of type (1):



beadboard --- Panels of plywood or other composite material that have a uniform series of various shapes of indentations running vertically so that the panels appears to be an installation of individual planks.

beading and parting tool --- A lathe tool that looks exactly like a squat parting tool and in fact is used as a wide parting tool in addition to being used to form beads. When the tool is used as a parting tool, the cutting edge is kept parallel to the axis of rotation of the spindle and the tool acts like a scraper just like a regular parting tool. When the tool is used as a beading tool, the cutting edge is rotated through a sweep and is not parallel to the axis of the spindle and the edge slices the wood rather than scraping it. Examples:



beading scraper --- synonymous with beading tool

beading tool --- A lathe tool; a small chisel used to form beads on a spindle. There really are two totally different types of beading tools. The first has a curved cutting edge and LOOKS like what one would use to form a bead, and the second has a square cross section and a flat cutting edge and looks like a squat parting tool. This second form comes in two flavors, depending on the way the end is shaped. When the end is cut as a wedge, so that the tool looks exactly like a squat parting tool, it is called a beading and parting tool. When the end is just sliced across, it is called a bedan. Both of those terms show their own illustrations, and what is shown below is the first form, the one with the curved cutting edge, which is used to scrape the spindle to create a bead. Examples:



beam --- (1) A structural member, generally laid horizontally or at a shallow angle to the horizontal, that supports a load that is applied at a right angle to its length. I have not seen any size definitions, but in general use the word beam implies fairly large and hefty. A beam is normally rectangular-cut lumber, but it could be a log (as it most certainly would be in a log cabin). Beams may also be made of composite material, particularly glulam. A really large beam that supports other smaller beams may would usually be called a girder. The term "beam" is somewhat loosely defined and structural members that are sometimes called beams often have more specific technical names (e.g. rafter).

bear scratch --- A particular type of figure in maple (at least that's the only wood I know of that it exists in) that may or may not actually be caused by a bear scratching the tree. although it certainly looks as though it might be. Here's an example:

need to add bearscratch pics


bed --- As regards woodworking, this generally means some flat surface that is the base of an operation. For example, the flat part of a table saw or radial arm saw where the wood rides is called the bed. In a pickup truck, the flat surface in the back where you throw things is the bed. On a lathe, the bed is the pair of horizontal rails that join the headstock and the tailstock and over which the turned part is positioned. A wood lathe bed is illustrated with wood lathe. On a lathe bed, the rails are called the ways.

bedan --- A chisel-shaped lathe tool used for spindle turning in a similar way to a skew chisel, but very specifically for turning beads. The tool looks a lot like a beading and parting tool except that the cutting edge is on the top of the shank and there is a single face below the edge instead of two faces meeting in the middle as there is on the beading and parting tool. This tool is sometimes used as a parting tool for wide parts, but its primary use is as a skew for forming beads. Examples:



bed gap --- On a wood lathe there is often an extra deep area of the bed right next to the faceplate so that face turnings can be done with a larger swing than is available for spindleturning.

bee's wing --- A small-scale, very tight, mottle figure is sometimes referred to as "bee's wing" figure due to the similarity with what the wing of a bee looks like. Technically, it is irregular ray waviness on a radial face. East Indian satinwood is extremely well known for having this figure, and it also occurs occasionally in narra, mahogany and eucalyptus. So when is a figure "block mottle" and when is it "bee's wing" ... well, pretty much whenever a particular dealer decides that's what they want to call it. Actually, a bee's wing is somewhat like a razor mottle that has been jumbled up and then reduced in size. Below is a composite pic with bee's wing figure in (1) santos rosewood, (2) eucalyptus, (3) eucalyptus again , and (4) andiroba. To see more pics of wood with this figure, click here: bee's wing pics



bell metal --- A kind of bronze, usually about 3/4 copper and 1/4 tin, used for making large bells.

bellows --- An instrument with an air chamber and flexible sides, for drawing in air and expelling it under strong pressure; used for blowing on fires (e.g. in a forge) to increase the rate of combustion so as to provide greater heat. Examples:



belt sander --- A form of power sander that uses continuous loop belts of sandpaper. In theory, this eliminates the small chatter produced by a drum sander because of the small open section in the sandpaper, but in practice the joint in the belts sometimes does the same thing. Belt sanders come in stationary floor models, smaller table top models, and and hand held portable models. The length and width of the belt varies greatly. The various types of belt sanders are listed in this glossary as follows:

belt sander, benchtop combo (belt and disk) --- This is a benchtop model power sander that is very similar to the floor model combo sander although it may have a narrower belt. These are handy for all sorts of sanding jobs. Compare/contrast to other forms of the belt sander. Examples:



belt sander, benchtop with narrow belt --- Compare/contrast to other forms of the belt sander. Examples:



edge sander --- This is a power sander with a belt stood on edge, designed primarily for sanding the edges of planks as opposed to their faces. Compare/contrast to other forms of the belt sander. Examples:



belt sander, floor model combo (belt and disk) --- This is a floor model power sander that is very similar to the benchtop model combo sander but with legs and sometimes a wider belt. These are handy for all sorts of sanding jobs. Compare/contrast to other forms of the belt sander. Examples:



wide belt sander --- This is a large, floor model, power sander with a belt that can range from about 18" wide to several feet wide. There are models that have belts wider than 4' so that they can sand the surface of a standard sized panel; these models are VERY expensive. This is not really a hobbiest's tool but something you would find in a commercial wood shop. Compare/contrast to other forms of the belt sander. Examples:



belt sander, handheld with narrow belt --- This is a hand held power sander with a narrow belt. These come in both pneumatic and AC power models. Compare/contrast to other forms of the belt sander. Examples:



belt sander, handheld with standard belt --- If there is anything "normally" meant by the term "belt sander", this is it. It is a hand held power sander with a belt, usually about 3" wide and 24" long, used for rough surfacing and miscellaneous sanding tasks. Compare/contrast to other forms of the belt sander. Examples:



bench dog --- A square or round rod of wood or metal that is placed in a corresponding hole in the top of a workbench to provide lateral support for a workpiece that is lying flat on the benchtop. Usually such a workpiece will be clamped between the bench dog and a vise dog, but bench dogs are also used just to provide a stop on one side of a workpiece so that it doesn't slide when pressured by a tool such as a plane. Bench dogs may have a head or not; they can be something as simple as a dowel stuck in a round hole in the bench top to a complex, jointed metal device with lots of flexibility in usage. Many versions have a spring strip on one side to keep them from slipping back down into the bench top while the work piece is being positioned. Metal versions may or may not have rubber or leather padding to prevent marring of the workpiece. See also bench stop for a somewhat similar device. Examples:



bench grinder --- A very simple but effective and extremely useful bench mounted power tool that has a center-mounted motor on each side of which is a wheel on a shaft that comes directly off of the motor. The wheels can be abrasive material for grinding metal or sharpening metal tools or they can be soft wheels for buffing or polishing or they can be wire brush wheels for cleaning or removing rust from metal objects. Although this is not directly a woodworking tool, no woodworking shop should be without one. Grinding wheels designed to be used on steel should NOT be used on soft metals such as aluminum or copper, as these metals will quickly get lodged in the pores of the wheel and make it smooth, thus preventing proper grinding operation. I can personally attest to that since back in my younger days when I didn't believe in reading directions, I ground aluminum on one and it did indeed ruin the wheel. Typically, a bench grinder will have only one speed, about 3400 RPM and they usually come with two grinding wheels of different composition, one for fine grinding and one for coarse grinding. Some come with a small lamp attached to illuminate the work and most have an adjustable tool rest and a clear plastic spark guard. The "usual" model has a 6" diameter wheel and a 1/2 horsepower motor, but there are versions with an 8" diameter wheel and a 3/4HP motor. Even larger industrial models are available. A version with its own stand is the pedestal grinder. Examples:



bench stone --- Any sharpening stone that is mounted in or on a bench to give it a firm base against movement while an edge is rubbed on it. Bench stones are normally rectangular, on the order of 2" wide, 5" long and less than 1" thick, and often have two different grits on the two sides.

bench stop --- A flip-up tongue that is permanently inlaid into the top of a workbench and acts the same as a bench dog; either as a stand alone stop to keep a workpiece from sliding, or in conjunction with a vise dog. Examples:



benchtop table saw --- This is the poor man's variety of table saw. It has most of the capabilities of a full sized contractor table saw but scaled down and it has the great advantage of sitting on a bench top when needed and not taking up shop floor space when not in use. I have even ripped and crosscut 4'x8' panels with a benchtop saw, although I had to put it out in the driveway and add temporary supports on the sides and at the outfeed and I can't say it was a terribly accurate cut. There are models available with a cart that both raises the saw to bentop height without taking up benchtop space, and which also makes the saw more easily portable. Compare/contrast to cabinet saw, hybrid saw, and contractor saw. Examples:



bench vise --- There are two significantly different types of vises that are referred to as bench vises. The first is used by woodworkers and the second is used by machinists. There's no rule that says either one is limited to one audience, but their design is based on their use. I have put them in this glossary as the woodworking bench vise and the machinist's bench vise, with full descriptions and illustrations with those terms. Here's a quick look at the two types:



bending strength --- The ability of a member, such as a beam, to resist the tendency to break when exposed to external forces, such as roof or floor loads, that tend to cause the member to bend.

bent --- The characteristic of carving tools that have a crank or dogleg along their length; see short bent and long bent.

bent shank chisel --- synonymous with cranked chisel

bevel --- (1)[noun] The part of a tool which is ground to form the cutting edge.
bevel --- (2)[noun] A surface that meets another at an angle other that a right angle. See also chamfer
bevel --- (3)[verb] To cut edges or ends at an angle, but not a right angle. See also chamfer.

beveled --- Having the edges where two surfaces meet removed lengthwise at an angle. See also chamfered.

beveled lap scarf--- A lap scarf joint that has the added complication of the laps being angled like half-dovetails. I don't see that this joint really provides much extra strength over a standard lap scarf, unless the planks are constrained from moving up and down relative to each other in which case the dovetail nature of the beveled lap would have a good effect. Examples:



BF --- Board Foot

bifold door --- A type of sliding door made from two (or occasionally more) hinged panels that fold as the door is slid sideways. Often used on closets in the USA.

big box --- A reference to the very large stores such as Home Depot, Lowes, etc. that sell woodworking tools, composite material, and sometimes wood.

billet --- As regards woodworking, this is an ambiguous term that usually refers to a rough length of wood that is to be spindle turned on a lathe but also sometimes is used to refer to shorts but also can mean a small stick and also refers to a round piece of wood such as a chair back spoke or a wheel spoke.

billhook --- A long-handled, hook-bladed large knife used for cutting branches and smaller wood plants such as shrubs and bushes. The sizes and shapes are all over the map on these, so here are a whole bunch of examples. Note that the scales of the various pics were not the same, so this composite pic distorts relative sizes.



binder --- An ingredient or blend of ingredients that holds the pigment particles together in a finishing agent. This is one of the nonvolatile ingredients of finishing agents.

biodegrade --- a form of wood defect where the degradation is via biological mechanism as opposed to, for example, a drying defect which has a mechanical cause. Some of the forms of biodegrade include:

bird hole --- Some birds make nests in natural hollows in trees but others make their own hollows by pecking out wood. These bird-created holes cause sections of irregular grain which (in addition to the holes themselves of course) make that area of a log commercially unusable.

bird peck --- Birds peck on trees primary to cause panic in the little insect critters that are eating away at the phloem. This causes the insects to come out and the birds then eat them. This pecking can cause small injuries to the tree that result in various grain changes that later show up as various forms of figure in the wood. With some birds, such as woodpeckers, the injury is more severe. The term bird peck refers to the resulting distorted grain. Bird peck can sometimes also result in small bark pockets and/or it may result in streaks of discoloration along the grain.

bird's eye --- A few woods (most notably hard maple but also anigre and a few other hardwoods) sometimes have large numbers of small round or elliptical "defects" that do indeed resemble the eyes of birds. This is caused by local fiber distortions but I have not found any explanation of WHY these fiber distortions develop. The density of the eyes ranges from sparse to dense, and the definition of "dense" frequently depends on the greed and/or honesty of a seller, so this is not a good figure to buy sight unseen. A good, truly dense, bird's eye maple board can make a spectacular addition to a project; it is very popular for jewelry boxes.

When cut into veneers, the logs are most often rotary cut or half-round sliced (in an arc) to produce the most uniform distribution of nice round eyes. There are a few woods that are sold as "bird's eye" with a density of eye figure so low as to make the term a joke. Zebrawood in particular comes to mind for this. I have seen zebrawood veneer sold as "bird's eye" due to having literally 8 to 10 eyes in an area of 5 or 6 square feet.

Below is a composite pic of 6 pieces of bird's eye maple veneer ranging from low density to high density. In each, the area shown is about 4 inches wide . To see more pics of bird's eye wood, click here: bird's eye pics



bird's mouth --- (1) a notch in a rafter where it sits on the supporting beam. See illustration below.
bird's mouth --- (2) A notched plate of metal or wood that is clamped or screwed to a bench so that the notch overhangs the edge. It is used to support work being cut with a piercing saw, fret saw, or coping saw. See illustration below.
bird's mouth --- (3) A type of joint used for creating hollow columns of wood for things like ship's masts, lightweight canoe oars, and planters. See illustration below.
bird's mouth --- (4) A router bit used to make the joint described in definition 3. See illustration below.
bird's mouth --- (5) A notched joint, generally in molding. See illustration below.

Examples of definition (1) bird's mouth notch [rafter joint]



Examples of definition (2) bird's mouth plate

need to add bird's mouth plate pics


Examples of definition (3) bird's mouth joint for cylinders



Examples of definition (4) bird's mouth router bit



Examples of definition (5) bird's mouth joint for molding



biscuit --- The flat oval wafer used in a biscuit jointer (their use is discussed there). These are usually made from pressed beech, but there are other materials available including plywood. There are three standard sizes, #0 which is 5/8" wide by 1 3/4" long, #10 which is 3/4" wide by 2 1/8" long, and #20 which is 1" wide and 2 3/8" long. The "official" sizes are expressed in metric units because the device was invented in Europe and you will occasionally see non-metric sizes that vary just slightly from those just given. Examples:



biscuit joiner --- One of the two major innovations in woodworking in the last 20 years (the other being the compound miter saw), this tool cuts oval slots in the edges or face of a board such that mating slots can be filled with glue and a flat oval wafer (called a biscuit and usually made of pressed beech, but also available in other materials including plywood). It was invented in Europe sometime around WWII but only came into widespread use in the last 20 years or less. The wafers expand slightly due to the moisture in the glue and the whole thing makes for a nice tight joint with good shear strength, much like a spline joint and because the slots never have to show at the edges of a workpiece, such joints always have the decorative advantages of blind joints. The biscuits come in three standard sizes and the tool is available in battery powered models. Examples:



biscuit joint --- Also called a "plate joint", this is a joint made with biscuits inserted into slots cut out by a biscuit joiner. Such joints have less strength than spline joints but are easier to make. Biscuit joints have the advantage of always being blind joints. Here is a wire-frame drawing of a simulated picture frame type of construction with a single biscuit (yeah, I know, it looks a bit like two biscuits, one on top of the other but that's just an artifact of Google Sketchup) inside a 45 degree mitered corner. This biscuit provides only moderate extra holding power to prevent the two sides from pulling away from each other perpendicular to the glue joint, but it provides a large amount of extra shear strength to prevent the sides from sliding past each other parallel to the glue joint.



bit --- The rotating cutting implement used in tools such as drills, routers, and Dremel tools. The designation sometimes has more to do with where a tool is used than in its shape; for example, there are spindle shaper parts, normally called "cutters" or "cutter heads", that are exactly the same outline as (though often larger than) similar-use router bits.

bit and brace --- see brace and bit

bitumen --- See asphalt

black knot --- synonymous with encased; a knot that is loose and may fall out.

black light --- Radiation at one end of the ultraviolet portion of the electromagnetic spectrum. It was wildly popular in the 1960's as part of the interest in all things "psychedelic" because it causes white cloth, and otherwise treated cloth, to glow brightly when there is no visible light. What does this have to do with woodworking? Well, one of the ways of identifying wood is that a very few of them fluoresce under black light. Here's an example of staghorn sumac under normal light and black light (the black light pic was taken in the dark, in terms of normal visible light). Most woods reflect absolutely nothing visible under black light, but as I said, a few do.



black line spalting --- The type of spalting in which the result is a series of sharply defined black lines, much like what you would get if you drew random, but continuous, lines on the wood with an ink pen. See spalted for an illustration.

blade --- (1) That portion of a tool or weapon that contains a cutting edge.
blade --- (2) The wider and longer leg of a steel square.

blade guard --- On a tablesaw, a plastic or metal shroud that covers the blade to prevent the saw operator from accidentally placing his hands in contact with the spinning blade. The device also prevents small cutoffs from being thrown back out towards the operator.

blade stabilizers --- Metal disks approximately 3 1/2" in diameter that go on one side, or both sides, of a saw blade to stiffen it to minimize flexing and increase its weight to minimize rim vibration.

blank --- A piece of wood that has been brought into very roughly the shape and size of the product that it is intended to become. Most often refers to pieces that will subsequently be lathe turned or carved. Typically this will be a cylinder for a bowl turning, and a relatively slender, square cross sectioned piece for turning between centers. For example a "pen blank" is a small piece of wood about 3/4" x 3/4" x 5" or 6" long and the pen-maker puts it on a lathe and turns off everything that doesn't look like a pen. See bowl blank for pics. For carving, a blank might be a shape cut out roughly on a band saw for subsequent fine carving to final shape. Examples:



blast gate --- A blocking mechanism in a dust collection system, used to shut off the suction to tools that are not being used and open the suction to the tools that are being used. This allows a single dust collection system to operate with fixed tubing to multiple tools in an efficient way. If all the tubes were left open all the time, it would require a large waste of power to provide enough suction to gather the dust from the tool(s) being used while also providing the same suction unused to the inactive tools. In well designed dust collection systems, it is typical to have all of the blast gates positioned at the top of a large chip collector tub that diverts wood chips out of the dust collection flow. Various commercial styles are available and many woodworkers build their own. Example:



blaze --- To mark a tree, usually by painting or cutting the bark. Forest properties often are delineated by blazing trees along the boundary lines. Frontiersmen in the early days of American colonization were said to "blaze a trail" when they left hatchet marks in trees.

bleaching --- The lightening, whether deliberate or accidental, of the overall color of solid wood or, more often, veneer, by the application of chemicals or UV radiation to cause a color shift towards white.

bleed --- A process whereby a substance such as natural wood resin permeates and stains the outer surface of a subsequent coating. See also resin bleedthrough.
bleed --- Any process involving a finishing agent whereby color migrates from one layer to another layer.

bleed out --- The process whereby internal resin in trees comes to the surface of cut planks. This is common on pine for example. Not to be confused with resin bleed through, which has to do with resin moving through a finishing agent.

blind --- (1) As regards woodworking, this generally means "not going all the way through", so for example a finial with a mounting hole that goes half-way through the wood could be said to have a blind hole.
blind --- (2) see blind joint

blind dado --- A dado joint (or cut) which does not go all the way from edge to edge but rather is only internal to the surface of the piece so that the edges are unbroken. If the dado cut does go through one edge but not the other, that's called a half blind dado or a stopped dado. If it goes all the way to both edges, it is a through dado. There is some confusion in nomenclature around the term blind dado in that some people use the term to mean what is actually the half blind dado. The true blind dado is rarely used, whereas the stopped dado is common and because the stopped ("half blind") dado is different from the through dado, it is often called the "blind dado" even though that is not technically correct. Also, The cut can go along the grain or across the grain, but if it goes along the grain, there is a more specific name, plough. Examples:



blind dovetail --- There are several ways to create a blind dovetail, including the two shown below. These are quite a chore to construct. The point is to totally hide the fact that it is a dovetail at all and just present a single clean straight joint line that makes it look like a rabbet joint but with the internal strength of a dovetail. In the examples shown, any attempt for the upper piece to pull upwards will be very strongly resisted by the dovetail. Also see mitered blind dovetail, which is even more complex. Examples.




blind edge rabbet --- see edge rabbet joint

blind end rabbet --- see end rabbet joint

blind fret --- fretwork that is created external to a workpiece and then applied to it with adhesive. Compare/contrast to open fret.

blind joint --- a joint, such as a dovetail or dado, in which the intruding piece does not go all the way through the receiving piece, or in some way offsets part of the joint so that the mechanism of the joint is hidden. For example, a simple butt joint of the end of one plank across the grain at the middle of another plank could be joined with a dowel joint, a biscuit joint, or a blind dado, and you would not be able to tell the difference among them because they are all blind joints.

Blind joints provide the strength of a through joint, but leave unbroken edges, or an unbroken face, on the receiving piece. Blind joints are generally more difficult to produce than through joints. Compare/contrast to through joint and half blind joint. The examples below show through and blind mortise and tenon joints and through and blind dado joints:



blind mortise --- see blind mortise and tenon

blind mortise and tenon --- A mortise and tenon joint where the mortise is not cut all the way through so that the tenon does not show on the face of the receiving piece; this is done to provide the joint strength of the mortise and tenon but to allow an unbroken surface on the receiving piece. Compare/contrast to through mortise and tenon. Some joints (e.g. dovetail and dado) have a version that is halfway between a blind joint and a through joint, and it is called a half blind joint, but the mortise and tenon does not have such a variety. The shortened tenon of a blind mortise and tenon is often called a "stub" tenon and the joint is sometimes called a stub (or stubbed or stopped) mortise and tenon. It is also called a "stopped mortise and tenon", but it is never properly called a "half blind mortise and tenon". Examples:



blind screw --- synonymous with set screw

blind splined miter joint --- Any miter joint can be splined, and the spline can be done so that the joint is either blind or half blind. Here is an example of a face miter joint with a blind spline:



blister --- (1) A small raised surface area, similar in appearance to the blisters that occur on human skin, usually on veneer (not as wood figure but as a raised bubble of mechanical origin) or a thin , or the surface of a finishing agent such as paint, and resulting from insufficient adhesive, inadequate curing, trapped moisture, an air bubble, etc.
blister --- (2) Wood figure that results when there is an uneven contour of growth rings and a log is rotary cut. The veneer, while smooth, appears to be covered with blisters. This is a term that, like many wood figure terms, is used very loosely by vendors and should be taken with some skepticism. You will often not be able to discern why a vendor used the term blister instead of pomelle. Blister occurs mostly in West African redwoods such as African mahogany, sapele and makore. Here are examples of blister figure in a few woods, or at least that is the description given to these by their vendors. The imbuia pics are mine but the other two are from a vendor who always makes her wood look shiny whether it is or not.



BLO --- Boiled Linseed Oil

--- A short plank or square of wood used as part of a parquet flooring. Also called "slats" in this context.

blockboard --- (1) synonymous with lumber core plywood
blockboard --- (2) A composite material very similar to laminboard except with a core formed of square-cross-section wood strips glued together instead of thin strips glued along their wide face. Very similar to lumber core plywood. Examples of the 2nd definition:



blocking --- The tendency of a finishing agent to adhere to itself on another freshly coated surface or to other substrates. Causes windows to bind, doors to stick and damage to finished surfaces when they’re contacted before the coating fully cures.

block mottle --- A form of mottle figure in which the mottle is moderately well organized and has moderately well defined edges. If it is less organized it is "normal" mottle (aka "broken mottle") and if it is more strongly organized and/or has sharper edges, it is called razor mottle. Below is a pic of block mottle makore veneer. To see more pics of block mottle, click here: block mottle pics.



block resistance --- The ability of a finishing agent to resist blocking.

blotch --- An area on the surface of the wood that have adsorbed more of a finishing agent than the surrounding area. Such a surface contrast is usually considered unattractive, so this is a term of disparagement.

blowdown --- Trees felled by wind. Also known as windfall and windthrow.

blow offs --- Roof shingles that have been forced off of a roof by high wind.

blue stain --- Also called "sapstain", this is a form of biodegrade in wood caused by a fungus that under certain conditions will spread into wood once the tree is removed from the stump (or sometimes when injured). The fungus eats nutrients found primarily in the sap, so it usually only occurs in the sapwood and not the heartwood. It does not occur in live trees because live sapwood does not contain enough oxygen to sustain the fungus. The color is the fungus itself rather than a chemically induced change in the color of the sapwood, and the presence of the stain does not in any way degrade the integrity of the cell structure (that is, it does not weaken the wood at all) and thus its presence does not count against wood in the grading process. Once present, its effect can be somewhat mitigated, but it cannot be removed completely. It is common in pine and maple but also occurs in many other woods such as anigre and aromatic red cedar. The color is usually blue but may also be gray and or even dark gray verging on black. The fungus can reach a tree as airborne particles or it can be deposited on them by flying insects, such as the pine beetle, which in turn gets it from the air or from another tree.

There are extensive articles on the internet discussing it and how to avoid it and even how to reduce its effect (but again, once it's there you can't get rid of it totally --- you need to avoid it during drying). It does not normally start to affect logs for many days, sometimes weeks or more, and of course, usually does not occur at all, but it CAN start immediately after cutting and have a pronounced affect within just a few days. One of my correspondents who uses a lot of aromatic red cedar tells me that it commonly occurs in that species within days of the tree being cut down. Below is a piece of aromatic red cedar with blue stain. For other pics of wood with blue stain, see blue stain pics.



blunting effect --- The degree to which a given species of wood reduces the sharpness of the cutting edges of tools such as circular saw blades and router bits.

board --- see plank for a discussion of "plank" and "board".

board and batton --- This describes a type of exterior siding or interior paneling that has alternating wide boards and narrow wooden strips, called battens. The boards are usually (but not always) one foot wide. The boards may be placed horizontally or vertically. The battens are usually (but not always) about 1/2 inch wide. These battens are placed over the seams between the boards. Reverse board and batten has very narrow boards with wide battens installed over the seams. Also known as barn-siding, because many barns in North America are constructed with board and batten. The words board and batten are hyphenated when used as an adjective, but not hyphenated when used alone. For example, we say: "My home has board-and-batten siding. Our builder constructed the house using board and batten." Sometimes reverse board and batton is simulated by solid panel construction that has narrow but deep recesses that create the kind of shadow effect created by true reverse board and batton. Examples:

need to add board and batton pics


board foot --- [BF] Any measure of board quantity that is the equivalent of a rectangle one inch thick and one foot wide by one foot long; that is, 144 cubic inches. When buying dimension lumber the amount of board feet is based on the nominal size, not the actual size. Boards thinner than 3/4" are usually sold by the square foot, not the board foot. When buying hardwood lumber the size calculations are based on pretty much the same reductions from actual size that are used with dimension lumber.

boat patch --- An oval (with pointed ends) repair section in plywood. Examples:

need to add boat patch pics


body --- Describes the consistency or thickness/viscosity of a finishing agent while it is still in liquid form.

boiled linseed oil --- An inedible, treated form of linseed oil used on its own as a wood finishing agent and as a constituent of other finishing agents. It is thicker and dries more quickly than regular linseed oil. Most products labeled as "boiled linseed oil" are a combination of raw linseed oil, petroleum-based solvent and metallic dryers. The use of metallic dryers is what makes it inedible. There are some products available that contain only heat-treated linseed oil, without exposure to oxygen but this type of linseed oil is thicker and dries very slowly and is usually labeled as "polymerized" or "stand" oil, though some types may still be labeled as "boiled".

bole --- The trunk of a tree from ground level to the first major branch; that portion of a tree trunk that is most commercially useful for producing lumber. Sometimes used as synonymous with trunk, but that is not correct; the bole is only a PART of the trunk.

bole wood --- The lower section of the trunk of a tree from the ground to the first limb or branch. Generally, this term is only applied to a tree that has grown to a substantial thickness, capable of yielding a sawlog, or pole. Also called "stemwood".

bolster --- [noun] As regards woodworking, this refers to a transverse load bearing structural component, particularly part of a wooden bunk bed or the floor of a wagon designed to carry long loads (such as logs or steel beams).
bolster --- [verb] Generically in English, this means to support (e.g. to "bolster his confidence").

bolt --- (1) A somewhat vague term used to describe short logs to be sawn for lumber or used for veneer (either slicing or rotary cutting) or to be used as pulpwood.
bolt --- (2) A uniform-diameter metal shank with screw-like threads on the outside (although not necessarily all the way up the shank) and a head of some kind that is used to turn the bolt. Bolts are not tapered, as screws usually are, and they have to be able to accept a nut that has a uniform internal diameter and threads. If something doesn't meet ALL of the aspects of that definition, then it isn't a bolt, it's a screw. One form of "headless bolt" is a set screw (and because it's headless, it's a screw, not a bolt). Bolts can be self-tapping as long as they still are able to accept a uniform nut above the self-tapping threads, so the fact that a shank is self-tapping doesn't make it a screw. If a bolt has a "screw driver" type head, such as a flat-head slot, that does not make the bolt a screw. If a bolt is very small, some folks have a tendency to call it a machine screw but that's really just another name for a bolt. Compare/contrast to screw and see also bolts vs screws. Examples:

need to add bolt pics


bolt cutters --- A cutting tool somewhat like a really long pair of pliers but with the hinge near one end and long handles to give very large leverage and with strong steel cutting jaws. Used for cutting bolts, as the name says, but also for cutting large wire and pretty much any metal objects up to reasonably moderate size (size somewhat depending on material; aluminum is a lot easier to cut through than steel). Examples:



bolts vs screws --- The bottom line is that if you have a fastener with a uniform diameter threaded shank (above any self-tapping area) that takes a nut and has a head, it's a bolt; otherwise it's a screw. Further discussion:

The most fundamental difference between a bolt and a screw is that a screw is tapered and a bolt is not. Another is that screw threads do not have to accept a nut but bolt threads do. Bolts have to have a head; a "headless bolt" (e.g. a set screw is not a bolt, it's a screw). The term machine screw is a widely used misnomer that really just means a small bolt, frequently with a head designed to be turned by a screw driver. The fact that a bolt is driven by a screw driver, does not make the bolt a screw. Neither overall size nor head type have any bearing on whether a fastener is a bolt or screw. Both bolts and screws can be self-tapping, but above the area of the self-tapping threads, a bolt has to be able to accept a nut with a uniform inner diameter and uniform threads. That is, the self-taping threads can be on a tapered end section of a fastener but if the part above that adheres to the definition of a bolt then the whole thing is a bolt and if not, it's a screw.

bond --- [noun] The adhesion of or ability of two items to stick to one another. This might be the union of materials by an adhesive or it could refer to a finishing agent's sticking to a surface.
bond --- [verb] To unite materials by means of an adhesive.

bonding --- see bond

bond strength --- The force required to break an adhesive assembly, with failure occurring in or near the plane of the bond.

bone dry ton --- [BDT] A measure of Wood pulp or residue that weighs 2,000 pounds at zero percent moisture content; also known as an ovendry ton.

book matching --- [also bookmatch] The matching of resawn boards or veneer sheets that mimics opening the pages of a book. That is, you have a board that has been resawn down its length or a pair of consecutive veneer sheets, and they are pressed against each other and then you leave the bottom edge touching and open the top pair of edges like opening a book. This produces a mirror image. A common problem in book matching veneer sheets is when the tight and loose sides are matched and reflect light and stains differently which can yield apparent color variations between the sides. This is more of a problem with harder woods and can sometimes be minimized by proper finishing techniques. Also, it is only a problem with veneer, not with resawn lumber, and occurs because of how the slicing process acts differently on the two sides of a veneer sheet. Here are several examples of bookmatched veneer sheets (I took all of these pics with the sheets just sitting side by side, so there are some gaps that would not be acceptable in a final project):



bore --- [noun] The hole for the arbor in a circular saw blade.
bore --- [verb] To drill a hole.

boring --- (1)[adj] Having to do with hole drilling. In most common use, the term often, but not always, refers to larger holes. One generally thinks of drilling a small hole and boring a large hole, but this use is not universal. Sometimes the term is used to describe the process of creating a hole when it is done with something other than a drill, even if the hold is small. A gimlet, for example, creates a small hole but is often said to bore the hole.
boring --- (2)[verb] The process of creating holes, generally large ones. Also refers to the process of opening up an existing hole (that is, increasing the diameter).

botanical name --- The scientific name for a wood. This name consists of a botanical genus, capitalized, followed by a specific epithet, in lower case, and the pair of terms taken together is the name of the species. For example, one particular species of white oak is called "Quercus alba". You may see it stated that the second term in a botanical name is the species but that is not correct. Botanical names are sometimes changed as scientists find out more about various types of wood, so a given species can have two totally different names, both given for perfectly good reasons, and these are called synonyms. Because synonyms have no apparent relationship to each other, and also because there can be more than one synonym, botanical names can at times be just as confusing as common names, although that is not often the case. For a more detailed discussion of the types of wood names, click here: wood names. For a sample list of botanical names and the corresponding common name, click here: botanical names

bottom plate --- see plate

bounce back --- The rebound of an atomized coating, especially when applied by conventional air spray methods. The air pressure used to atomize the coating bounces off the surface being sprayed keeping the material from attaching to the surface and it's lost as overspray.

bound moisture --- synonymous with bound water

bound water --- [also bound moisture] Water found within the cell wall of wood. Compare/contrast to free water and see the discussion with the term fiber saturation point

bow --- a drying defect in which both ends of a plank warp upward from the plane of the plank. That is, if the flat, rectangular plank, shown in black in the drawing below, were laying on a table top, the middle would remain on the table top but both ends would lift upwards, as shown in red in the drawing. The red arrows show the direction of the movement. Bow is one type of warp.



bowlblank --- A piece of wood that is destined to be turned into a bowl on a lathe and that has been put into roughly the size and shape of the final bowl prior to turning. Examples:



bowl coring system --- A cutting tool and tool rest that make up a system for coring out bowls in a way that allows for multiple, successively smaller, bowls to all be turned from the same bowl blank. The coring knife is a curved parting tool that cuts a bowl shape out of the front of a bigger bowl shape, and the process can be repeated multiple times depending on the size of the blank. Examples:



bowl gouge --- A type of lathe gouge specifically designed for face turning. Bowl gouges tend to be longer and heavier than spindle gouges and they also have a deeper flute. They are specifically designed to remove large amounts of wood from the curved sides of a turning bowl. The end bevel grind varies quite a bit on these gouges and there is a particular type of grind called a fingernail grind that makes the bowl gouge even more aggressive in removing material, and in fact many turners (myself included) much prefer the fingernail grind to a regular grind. However, the term "fingernail gouge" does not normally refer to a bowl gouge with a fingernail grind, but rather to a spindle gouge with a fingernail grind. See also lathe gouge shape comparison. The grind on bowl gouges will vary somewhat by manufacturer, even aside from the major differences between regular grind and fingernail grind. Also, there is more variety in the shape of the cannel on a bowl gouge than on a spindle gouge (where they tend to be circular arcs). Below are two sets of composite pics, the first with regular grind bowl gouges and the second with fingernail grind bowl gouges:


BOWL GOUGES WITH REGULAR GRIND


BOWL GOUGES WITH FINGERNAIL GRIND


bowl lathe --- A short bed, large swing wood lathe, often without a tailstock, that is used just for turning bowls.

bowl scraper --- A lathe tool; a variant on the round nose scraper in which the cutting edge is mostly on one side and continues along the body of the scraper (on that side) for an amount that varies by manufacturer, but which is more than what exists on a round nose scraper. The purpose is to provide a large cutting surface placed so that it is most useful when turning the insides of bowls. The "normal" bowl scraper is what is also known as an inboard bowl scraper, for reasons that are discussed with the term inboard turning. When turning the outsides of bowls, using outboard turning it is useful to have a tool where the cutting edge is on the opposite side, and that tool is the outboard bowl scraper. It should be noted, however, that many turners turn the outside of their bowls first, with the outside of the bowl pointing away from the headstock and then they remount and turn the inside; when using this technique, there is no need for an outboard scraper. Outboard bowl scrapers are not as widely available as regular bowl scrapers. Examples:



bowl steady --- A support device much like a backsteady but made to work with bowls to support them from the rear. Example:



bow saw --- (1) an old style hand-saw that can be used for several purposes. It has a blade, usually about a foot long but could be a couple of feet long, that is kept in tension by a wind-up tourniquet that is easily removed for blade change. Depending on the intended use, the blade width varies widely. It has wooden handles and long wooden uprights on both ends, all of which serve to provide a lot of room for grabbing, thus giving the operator good, and flexible, control. In addition to fine scroll work, it can also be used for cutting off tree branches and other obvious saw uses. European craftsmen traditionally use this form of saw in situations, such as crosscutting a plank, where British and American craftsmen would use what we call a hand saw. Because the blade is under tension, it does not whip the way a hand saw blade does and because of the ability to use various width blades plus the fact that the blade can be swiveled, this saw has MUCH greater versatility than a hand saw. This is one example of a type of saw called a "frame saw". Example:



bow saw --- (2) a modern hand-saw that bears only a remote resemblance to the old style bow saw (see definition directly above) and has almost none of the flexibility of its namesake. This is primarily a gardening tool, used for cutting branches. It has a blade that is kept under tension in a bowed steel frame by a tensioning handle that makes for very easy blade changes. Example:



bow stave --- [also bowstave] A long wooden stick used to make a bow (as in "bow and arrow"). Not all woods are OK to use for bow staves, only those (such as osage orange) that work well in bending situations.

bowtie --- synonymous with butterfly joint

box --- In addition to having the normal English language meaning (e.g. jewelry box, cigar box), in wood turning this term is also used for round containers, turned on a lathe, that a non-woodworker would not normally think of as a "box" since the very terms "box" and "boxy" imply a rectangularity that is not present in what I designate, in this glossary, by a term that I like even though I have only rarely seen it used, and that is lathe box.

box beam --- A beam consisting of two vertical sides (webs; usually made from composite material) and two horizontal members (flanges, usually boards) such that the beam has a rectangular cross section. Box beams provide good structural support because of their rigidity.

box cutter --- synonymous with utility knife

boxed heart --- synonymous with boxed pith

boxed pith --- Describes the condition where the pith of a tree falls entirely within the four faces of a single piece of wood.

box joint --- A corner joint made up of interlocking rectangular "fingers" of wood. Has good strength due to large gluing surface area, and also has great aesthetic appeal for many people. This joint is sometimes called a "finger joint" because of the way it looks, but that term is more appropriately applied to a different joint (see fingerjoint). Examples:



box nail --- A wire nail with a flat head; box nails are smaller in diameter than common nails. Box nails are used on thin material in place of larger nails such as common nails or even finishing nails, but like common nails, box nails have heads that are clearly visible after the nails have been driven. Box nails are the same length per penny size as common nails, but have narrower shanks and slightly smaller heads.

brace and bit --- A hand operated drilling mechanism. It has a crank shaped handle with a flat knob on the upper end and a two-jaw chuck on the lower end that holds special auger bits with a square tapered shank. This is an old style system but still works well when jobs are done by hand, and it is capable of drilling quite large holes. In a corner, the wide swing of the handle makes it impossible to use, but most versions have a ratchet that overcomes this limitation.



bracing --- Secondary structural members that normally do not support gravitational loads but are required to provide lateral stability to other structural members or to transfer horizontal loads to the supports. The stereotypical example is a diagonal beam supporting a sagging fence or building wall.

brad --- A small finishing nail; most definitions say brads are no more than 1" long, but you can buy them up to 1 1/2" long. They are wire nails and they are quite small in diameter. Large brads are about the size of a 2d nail in length but smaller in diameter. See the picture posted with the term nail. Brads are used for attaching small molding and are often used in the backs of picture frames to attach a thin piece of molding that holds the picture in place. There are a couple of specialty tools that help deal with brads, called brad setters.

brad point drill bit --- A twist drill bit with a sharp point (somewhat like a brad, thus the name) instead of the normal fairly dull point on a standard twist drill bit. These bits are for wood or very soft metal; the brad point allows very accurate positioning of the bit to enter at a precise point into the material being drilled. Most such bits have very sharp pointed edges at the outside bottom of each flute and you would expect that these would cut nice clean holes on exit, my own experience (and that which others have shared with me) is that the exit in most woods will be very splintered without a backing board. Examples:



brad pusher --- A metal cylinder with a concave tip on one end and a pushing handle on the other end; the concavity hold the head of brad (or sometimes a very small finishing nail, and you push it into place by shoving on the handle. Examples:



brad setter --- A tool for pushing brads into molding. Brads are small and are sometimes put in places where it is not feasible to use a hammer, so these devices aid in the brad insertion. There are two basic types, listed as separate terms in this glossary, namely:

brad squeezer --- A device that acts like a pair of pliers that has the peculiar characteristic of squeezing toward the hand of the holder. It is used, to squeeze brads into place, particularly when using brads to place thin molding at the back of picture frames to hold the picture in place, and also when just using not-fully-inserted brads to hold the picture in place. Examples:



branding iron --- A tool for burning a name or logo into a wood surface. It may be electric or flame heated. Numerous companies sell custom made branding irons for wood craftsmen.

brash --- Describes wood that characterized by brashness.

brashness --- An abnormal condition of wood characterized by low resistance to shock and by abrupt and complete failure across the grainwithout splintering. "Low resistance" means the break or failure usually occurs under comparatively small loads and deformations. Brashness has numerous causes including extreme growth rate (either very fast or very slow, depending on the wood), prolonged exposure to high temperatures and decay. Brashness in wood is similar in effect to brittleness in some materials such as glass and cast iron.

brass --- A metal that is an alloy of copper and zinc and that does not corrode the way steel does. It is also softer than steel, and it has a pleasing yellowish-gold color. Its use in woodworking can be either because of its relative softness (e.g. on the head of a carving mallet) or because of its appearance (e.g. decorative/aesthetic effects on the trim of such items as marking tools).

brazing --- a method of joining two similar or dissimilar pieces of metal by using a 3rd metallic element or compound which melts at a lower temperature than the other two. If the temperature is below 450 degrees Celcius, then the process is called soldering. If the temperature is above 450 degrees Celcius but below 800 degrees Celcius, then the process is called brazing. If the temperature is above 800 degrees Celcius, then the process is called welding, but unlike soldering and brazing, welding actually melts and fuses the two materials in addition to adding a third.

breakfront --- A piece of furniture, such as a cabinet or a bookcase, with a central section that projects beyond the sections to either side (and it is this broken-line outline that gives them the name). Despite the definition, the term is also used for similar pieces where the central section does not project out beyond the side sections. They come in a very wide variety of styles with prices ranging from expensive to very expensive to "if you have to ask how much, you can't afford it". When I was growing up, I always thought they were called breakfronts because the ones I saw had glass in the front sections and it just made sense to me that because you could break the front that you would call them breakfronts. Apparently I was wrong but I like my definition better anyway. Examples:



breast height --- As regards woodworking, this is a term used in tree descriptions and has the specific meaning of 4 1/2 feet above ground level. See diameter at breast height.

bridge --- see bridging

bridging --- (1) When a finishing agent forms a layer over a crack or void rather than filling it. The higher the viscosity of a finishing agent, the more likely this is to happen.
bridging --- (2) Bracing members installed between floor joists to stiffen the floor and distribute live loads. Also called cross-bridging.

bridle joint --- A type of mortise and tenon joint in which the tenon is open at the top; that is, the mortise is slotted all the way out of the edge of the piece it's in. As can be seen in the examples below, the joint can be half blind or through. A half blind bridle joint is also called a stopped bridle joint, and the joint itself is also called an "open mortise and tenon joint". Examples:



brindled --- A term that normally is used to described various kinds of streaking in cat fur, it is used in woodworking to mean "marked with streaks"; a flawed condition of an applied finishing agent.

brittle --- Refers to material that tends to break or shatter under stress, rather than stretching, bending, or otherwise deforming. Compare/contrast to ductile and malleable.

broad leaved --- In woodworking terms, this refers to gymnosperm (hardwood) trees.

broken mottle --- a little-used term that is synonymous with mottle

brown cubical rot --- a form of brown rot which attacks the roots and lower trunk of a tree and causes the heartwood to shrink and become brittle and break into large brownish cubes as seen in this illustration:



brown rot --- A form of wood decay, found only in softwoods, that destroys the cellulose and associated carbohydrates and leaves a brittle matrix of modified lignin, which tends to crack across the grain. Advanced brown rot tends to leave the wood more brown than normal, thus the name. In older times, this was synonymous with dry rot but nowadays it is looked at (more correctly) as a precursor to dry rot and the terms are not synonymous. That is, dry rot is what's left when wood that has undergone brown rot dries out and the modified lignin is a friable material that will crumble at the slightest pressure. A particular form of brown rot that causes the wood to break up into rectangular sections, is called brown cubical rot.

brown stain --- (1) A wood stain caused during kiln drying due to oxidization on or just under the surface of the wood. The staining is most likely to occur when fresh, unseasoned lumber is stacked and stored for several days during warm or humid weather prior to kiln drying. It is particularly likely when high kiln temperatures are used.
brown stain --- (2) A rich brown to deep chocolate-brown discoloration of the sapwood of some pines caused by a fungus that acts much like the blue-stain fungus.

browse --- As regards woodworking, this refers to the parts of woody plants (twigs, shoots, leaves, etc.) eaten by forest animals.

bruise --- To make a dent in wood by striking it with a hard object such as a hammer.

brush --- [noun] A group of animal hair or synthetic fibers bound in a metal retainer and used to apply finishing agents and adhesives to wood surfaces.
brush --- [verb] An application technique for putting finishing agents onto wood. Brushing is a quick method of application and very much the technique of choice for painting small or intricate surfaces where a roller is not practical. Brushing is sometimes inferior to wiping because brushing does not work the finishing agent into the wood as well as wiping and it also is more prone to air bubbles with some kinds of finishes (e.g. polyurethane). Also brushing can cause localized flooding which is a problem that wiping avoids; on the other hand, wiping does not do as good a job as brushing at getting into small crevasses.

brushability --- The ease with which a finishing agent can be applied with a brush.

bruzze --- This is the name of a particular type of joinery chisel that is also known as a corner chisel but that term also refers to another type of corner chisel that is illustrated with that term. The bruzze (as opposed to that other type of corner chisel) is what one normally thinks of as a joinery chisel and at the end of the normal handle and shank, it has a thick right-angle cutting end that is used to clean out corners. Examples:



BTU --- British Thermal Unit, a measure of energy. Specifically, it is the energy required to heat one pound of water from 59 degrees fahrenheit to 60 degrees Fahrenheit at sea level. To give some sense of what this means, think of it this way. To keep a 100 Watt light bulb going for one hour would take about 340 BTUs. Comparisons of wood and other fuels are a little messy because most of the others are normally measured in gallons, not cubic feet, but I've done some conversions and here's a very rough comparison of a range of woods and a couple of other fuels. Keep in mind that seasoned wood produces twice as much energy as green wood and this table is talking about seasoned wood:

material BTUs per
cubic foot
of material:
coal 1,630,000
fuel oil 1,040,000
butane 760,000
propane 680,000
hickory 216,000
hackberry 162,000
basswood 105,000


bubble free veneer --- A layer of veneer applied to a double paper layer of two 10 mil papers (see ten mil veneer). With moisture resistant glue, the overall backer thickness is 22 mils and the whole construct is pretty well guaranteed not to have bubbling or other defects due to thinness.

bubbles --- see bubbling

bubbling --- (1) The condition in which bubbles of air or solvent vapor are present inside layers of an applied finishing agent that has cured.
bubbling --- (2) The creation of raised areas in a veneer that has been bonded to a substrate; generally caused by moisture acting on thin veneer.

buck --- A logging term meaning to cut felled trees into shorter lengths, such as a href="#log">logs or cordwood.

buckling --- The condition where a wrinkle or ripple or bowed area affects roofing shingles or their underlayment. If the underlayment contains the buckling, it is almost certain to be telegraphed to the shingles.

buff --- [verb] To rub a surface with a polishing cloth in order to bring it to a bright shiny finish.
buff --- [adjective] A light tan/brown color.

built up work --- A workpiece which is made by gluing together two or more pieces of wood.

bull nosed step --- A staircase bottom step with bull nosing.

bull nosing --- No, this is not a large horned mammal sticking the front of its face into something, it's a reference to a curved side extension of the first step at the bottom of a staircase, made to accommodate volutes and turnouts. Examples:



bumps --- see surface bumps

burl --- A wart-like, deformed growth on the trunk or root and sometimes even the branches of a tree, caused by (1) an injury to, or (2) and infection in, the tree just under the bark, or (3) the existence of an unformed bud which has all the genetic material necessary to grow a full branch, or even a whole tree, but which for some reason did not grow properly. In any case, the result is that the tree cells divide and grow excessively and unevenly in a process somewhat analogous to cancer cells in a mammal. Burls are sometimes called tumors on wood, although I'm not aware of their ever being fatal. Trees with burls continue to grow otherwise normally.

Continued growth follows the contour of the original deformity, producing all manner of twists, swirls and knots in the wood fiber. Usually, this results in wood that has a spectacular pattern that can be used to great effect in woodworking, and sometimes it is also accompanied by the creation in the burl of dormant buds which create eyes that make the burl even more spectacular when worked.

Burl wood is usually darker than the rest of the tree and in some cases (Paela comes to mind) may be a significantly different color altogether. Because of the diverse grain direction, burl wood cannot be relied on for strength, but that's of little consequence since burls are prized for beauty, not strength.

Burl wood can be difficult to dry without cracking. Sometimes there are bark inclusions in burls, and also sometimes gum pockets and other voids, any of which can cause surface defects when the burl is worked. Root burls are particularly prone to voids. In some species of wood, gum pockets are common in any burl found on the tree.

Burls come in all sizes and shapes from golf-ball and smaller to hundreds of pounds of massive growth on the side of a large tree. Burls as large as 4 feet by 8 feet have been reported as have trees with hundreds of small burls. On really large trees, such as the redwood, burls commonly exist that are large enough to be used to create veneer. Burl veneer frequently does not stay flat after cutting and has to be moistened and clamped flat before and/or during application.

A couple of commonly identified types of burl figure are Cat's paw and cluster burl. Cat's paw is frequently found in cherry and cluster burls are found in a number of species. Most often, burls have no sub-designation and occur in a large number of species. Common burl species include redwood, oak, ash, maple, madrone, elm and walnut. Some exotics with very popular burls are mappa (poplar burl), thuya and imbuia, and there are MANY more.

Below is a composite pic with several burls which just scratches the surface of the enormous variety of figure that exists in burls. For a look at more burls, click here: burl pics



burnish --- (1) To make shiny by friction caused by rubbing / polishing. In wood lathe turning, this is done by holding a handful of wood shavings, left over from the turning, against the revolving workpiece. Care needs to be taken if the workpiece has any sharp edges, as these will tend to scorch if the burnishing is too vigorous. Burnishing can also be accomplished by using leather, worn sandpaper, and other materials.
burnish --- (2) To flatten the working edge of a cabinet scraper with a burnishing rod in order to create a slight overhang of metal that acts as a fine cutting edge for the scraping action.

burnisher --- see burnishing rod

burnishing rod --- A very hard cylinder or triangular cross section length of steel, with a handle, that is used to flatten the working edge of a cabinet scraper and create the hooked overhang of steel on the scraper that is its cutting edge.

burr --- (1) British for burl
burr --- (2) A fine, thin razor-sharp projection, sometimes called a "wire edge", left on the edge of a cutting tool when it is ground to sharpness. For most tools such as knives and carving chisels, the burr is removed by honing but for a cabinet scraper the hook-shaped burr left by a burnishing rod is often left on and made use of in the first few strokes, which both use its cutting power and also remove it at the same time. Similarly, a woodturner may leave the burr on a freshly sharpened lathe scraper for the same reason.

bush --- Anything that looks like a small tree but doesn't meet the definition of "tree"; a low-growing woody plant with lots of branches. Also called a "shrub".

butt --- (1) the end of a plank (as opposed to the side)
butt --- (2) The base of a tree
butt --- (3) The large end of a log
butt --- (4) The first cut above the stump of a tree.

butt cut --- (1)[verb] To cut off a tree right at the stump. Since the stump is what's left when then tree is cut down, this seems to me like a circular definition.
butt cut --- (2)[noun] synonymous with butt log

butterfly joint --- A "joint" that is most often used as an elegantly decorative way to strengthen an area that is weak or cracked, particularly when using entire planks to create a bench or a table top. It can also be used as an edge joint for undamaged planks but the highly visible nature of the joint means that aesthetics are a consideration more than would be the case with many joints. The basis of the joint is a piece of wood that is in the shape of a back-to-back pair of dovetails which together form the shape of butterfly wings, thus the name. Also called a "bowtie" because of the shape. Examples:



butt joint --- Most formal definitions give this as "A joint formed by abutting the squared edges of two pieces", which of course can mean any two edges, but this seems wrong to me, since the "butt" of a plank is the END, not the edge and in common usage, "butt joint" far more often agrees with my own sense that it means butting the ENDS of two planks. The phrase "to butt up against" is even more vague and can even encompass face to face "butting", so I consider this to be a vague term. Examples:



butt log --- A log cut from the bole immediately above the stump.

buttress --- A lateral ridge of wood at the bottom of a tree trunk that helps to stabilize a tree growing in wet soil or water where a normal deep root system is not possible for the tree. Buttresses start below the ground (or water) level and may go up many feet onto the trunk of the tree. One of the largest-buttressed trees is swamp cypress. There are some trees that grow huge buttresses. I've seen pics of ones that had to be 15 feet high, maybe 20. Examples:



butt rot --- Decay confined to the base or lower bole of a tree.

buzz saw --- synonymous with circular saw


for images of wood itself, go here -> wood id site
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