Instrument for determining log and tree diameters by measuring their rectangular projection on a straight graduated rule via two arms, one of them sliding along at right angles to the rule itself. The optical caliper determines upper, out-of-reach diameters through an optical system incorporating two parallel lines of sight separated by a variable baseline.
Cambium
The live, actively growing layer of a tree. The cambium is one cell thick and resides between the phloem and sapwood. It repeatedly divides itself to form new wood which causes the tree to expand and grow. It is the layer that becomes either bark or wood and lays dormant during winter.
Canadian Standards Association (CSA)
A non-profit organization that has developed over 2,000 different standards for a variety of industries.
Canary
Heartwood varies from pale-yellow-brown to pale olive-brown streaks
Usually straight and regular grain
Medium density
Used for pattern making, musical instruments, cabinets, interior trim for boats, toys and doors
Canopy
A continuous cover of branches and foliage formed collectively by adjacent tree crowns.
Cantilever
The allowable overhang past the joists or rim joists.
Cant
A log that has been debarked and sawn square.
Cap Rail
The top horizontal piece of a railing placed to give it a finished appearance.
Carcase
The body of a piece of furniture with a box like shape.
Carbide Tipped
Extremely hard steel pieces with sharp cutting edges fastened to cutting tools such as saw blades, and router bits.
Carload
A railroad car loaded to meet railed minimum weight requirements for carload rates. The volume in a carload may vary, depending upon the type of lumber loaded and the size of the car.
Card Scraper
A flat blade with a burred edge used for smoothing.
Carpenter’s Pencil
Rectangular shaped pencil, about 1/4”x ½”, with a 1/16” x 3/16” lead.
Carriage Bolt
A bolt with a rounded head that is pulled down onto the surface of the wood as the nut is tightened. It's used to hold structural members together, as the rounded head gives a finished look to the bolt. Bolts should be checked annually and tightened when necessary.
Case Hardening
A defect in lumber caused when a board is dried too fast, or improperly. The outer layers in a case hardened board are compressed while the inner layers are in tension.
Casing
Usually run to pattern and is widely used for interior trim.
Cat’s Paw
A person used by another as a dupe or a tool.
Catalyst
A substance that initiates or changes the rate of chemical reaction but is not consumed or changed by the reaction.
Caul Veneering
A method where the veneers are cut square, taped together and laid as a single sheet without preliminary dampening.
Caulking Seam
A machined groove or depression worked in the wood. It provides a weather resistant joint when filled with caulking material and fitted with an adjoining piece.
CB
Center Beaded
Cedar
Any spreading evergreen conifer of the genus Cedrus bears tufts of small cones and needles. In full cedar wood, the fragrant durable wood of any cedar tree. Cedar lumber provides one of the best choices for deck construction, although more expensive than the cheaper options, it will last much longer because of its natural decay resistant and insect repellant properties.
Ceiling
A lumber pattern featuring a center and edge V and/or bead.
Cell
The smallest, microscopic structure in wood.
Cellulose
The carbohydrate that is the principal constituent of wood and forms the framework of the wood cells.
Cement
A powder that serves as a binding element in concrete and mortar. Also, it is an adhesive.
Center Beaded
A patterned lumber shaped to form a narrow half-circle along the center of its length.
Center Match (CM)
Lumber that has been worked with a tongue exactly in the center on one edge of each piece and a groove on the opposite edge to provide a close tongue-and-groove joint by fitting two pieces together.
Center V (CV)
Patterned lumber shaped to form an angled groove along the center of its length.
Center-to-Center Spacing
The spacing between structural members determined by measuring from the center of one to the center of the next. (i.e. 16-inches o.c.)
Chain Saw
A saw that is powered by an electric motor, gasoline, or hydraulics; cutting elements are on an endless chain similar to a bicycle chain.
Chalk Line
An enclosed reel of string coated with colored chalk and used to mark straight lines by pulling the string taut and snapping the string, leaving a line of chalk marking a line. Commonly used in deck building to mark the edge of decking so that all decking boards can be cut off flush with each other.
Chamfer
A bevel or slope created by slicing off the square edge or end of a piece of wood or other material (usually 45 degrees); a decorative edging or relief made at the timber’s corner.
Check
A lumber defect caused by uneven shrinking of the wood during drying. A checked board has splits that develop lengthwise across the growth rings.
Check Scaler
A person who rescales logs in order to detect errors in the initial scaling.
Chemical Pulping
A process in which wood fibers are separated by removing the lignin and other wood components through the use of chemicals.
Chemical Thinning
Any thinning in which the unwanted trees are killed by chemical poisoning; band or frill girdling may be done at the same time.
Cherry
Heartwood varies from rich red to reddish-brown
Fine, straight, close grain
Smooth texture
Good wood bending properties
Low stiffness
Medium strength and resistance to shock loads
Takes an excellent polish
Used for tobacco pipes, musical instruments, furniture, cabinets, boat interiors, decorative veneers, and wall paneling
Chip
A small piece of wood used to make pulp. Chips are made either from wood waste in a sawmill, pulpwood operation, or from pulpwood specifically cut for this purpose.
Chipboard
A paperboard used for many purposes that may or may not have specifications for strength, color, or other characteristics. It is normally made from paper stock with a relatively low density.
Chip-n-Saw
A registered trade name for a machine that makes small logs into cants, converting part of the outside of the log directly into chips without producing any sawdust. Cants are then sawn into lumber as part of the same operation.
Chipped Grain
A machining defect in which small chips are torn from the surface below the intended plane of cut, usually as the result of cutting against the grain.
Chisel
A metal tool with a sharp beveled edge, used to cut and shape metal, stone, or wood.
Chord
The bottom or top member of a truss to which the web members are attached.
Chop Saw (Miter Saw)
A hollow-ground saw in diameters from 6 to 16 inches, used for cutting off and mitering on light stock such as moldings and cabinet work.
Chuck
An attachment to hold work or a tool in a machine; lathe chucks and drill chucks are examples.
CIF
Cost, Insurance, and Freight
CIFE
Cost, Insurance, Freight, and Exchange
Circular Saw
A power saw that has a steel disk with cutting teeth on the periphery; rotates on a spindle.
Cladding
The application of one material (metal, wood, vinyl) over another to provide a protective layer against rain, and other weather elements. Cladding is designed to prevent water from infiltrating the structure and is not "waterproof." It is also chosen for architectual design.
Clamp
A fastening device to hold or secure objects tightly together to prevent movement or separation through the application of inward pressure.
Clear (CLR)
A board which is free from defects. A term including the higher grades of lumber sound, relatively free of blemishes.
Clear-Cut
Cutting all trees in an area to a minimum diameter, such as 4 inches.
Cleavage
In an adhesively bonded joint, a separation in the joint caused by a wedge or other crack-opening type action.
Clevis
“U”-shaped metal fitting, with a pin connecting the two ends, used for connecting cables and rigging the “C” shaped hook with a pin through it for use in attaching or towing a cable.
CLF
Hundred Lineal Feet
CLG
Ceiling
CLIB
California Lumber Inspection Bureau
Climax Species
Plant species that remains essentially unchanged in terms of species composition for as long as the site remains undisturbed.
Clinometer
A hand instrument used by foresters and timber cruisers to measure vertical angles. Such angles, when correlated with specific distances, indicate the height of standing trees.
Close Grain
Wood with narrow and inconspicuous annual rings; the term is sometimes used to designate wood having small and closely spaced pores, but in this sense, the term “fine textured” is more often used; wood with more than six rings per inch
Closed Coat
A piece of sandpaper whose surface is completely covered with abrasive particles. This type of paper tends to clog easily with sawdust and is not popularly used for woodworking.
Coarse-Grained
Wood with wide and conspicuous annual rings; rings in which there is considerable difference between springwood and summerwood; used to designate wood with large pores.
Cock Bead
Any bead which stands raised from the surface as distinct from flush or sunk; usually taken to apply to small beads or edgings to drawer fronts and cupboard doors.
Cocobolo
Very heavy, tough, strong timber
High mechanical strength
Rich red heartwood
Irregular grain
Fine uniform texture
Used for cutlery handles, small tool-handles, small trinkets, fancy goods, wooden jewelry, and small decorative items
Codes
Regulations detailing accepted materials and methods of building. Usually codes are adopted by city, county, or state building departments. Most counties promulgate local building codes.
Cohesion
The state in which the constituents of a mass of material are held together by chemical and physical forces.
Cold Pressing
A bonding operation in which an assembly is subjected to pressure without the application of heat.
Collapse
The flattening of single cells or a row of cells in hardwood during the drying or pressure treatment of wood characterized externally by a caved-in or corrugated appearance.
Collar Tie
A timber placed horizontally and between rafters that control sagging or spreading of the rafters; usually placed parallel to the grits which connect rafter pairs at a given height.
Collet
In a router, the sleeve that grips the shank of a bit.
Colonial Siding
AKA "Bevel Siding" is exterior cladding used for weather protection and architectural design.
Column
A structural member, usually subject to longitudinal compression.
Combination Square
A square that measures both 45 degree and 90 degree angles.
Come Along
A hand operated ratching wrench. It uses include tightening joinery during assembly, as a safety tie and for pulling frame components together during erection.
Commission Man
A middleman who arranges sales for a commission but does not take title to the lumber.
Commons
Ordinary grades of knotty lumber.
Common Grade Lumber
Lumber with obvious defects.
Common Rafters
Closely and regularly spaced incline timbers that support the roof covering; independent of the bent system.
Compass
An instrument for drawing circles consisting of two legs joined at a pivot hinge.
Compreg
Wood in which the cell walls have been impregnated with synthetic resin and compressed to give it reduced swelling and shrinking characteristics and increased density and strength properties.
Compression Failure
Deformation of the wood fibers resulting from excessive compression along the grain either in direct end compression or in bending.
Compression Wood
Abnormal wood that often forms on the lower side of branches and of leaning trucks of softwood trees; compression wood is identified by its relatively wide annual rings, usually eccentric, and its large amounts of summerwood, usually more than 50% of the width of the annual rings.
Composite Assembly
A combination of two or more materials bonded together that perform a single unit.
Compound Curvature
Wood bent to a compound curvature, no element of which is a straight line.
Compound Cut
An angled cut to both the edge and face of a board.
Compound Miter
An angled cut to both the edge and face of a board; most common use is with crown molding.
Composite Decking
Deck boards manufactured from wood fiber and plastic. It is sold as an alternative to wood decking. There are various composite decking manufacturers with varied degrees of quality which can lead to low product quality.
Concave
An inward-curving shape.
Concentration Yard
Assembles and ships the output of a number of nearby sawmills.
Concrete
A mixture of cement, gravel and sand.
Concrete Mixer
A machine with a large revolving drum in which concrete is mixed with other materials to make concrete.
Concrete Spatula
A flat piece of metal with a projecting handle used to smooth concrete footings.
Concentrated Load
The application of a relatively large force on a relatively small area.
Conditioning
The exposure of a material to the influence of a prescribed atmosphere for a stipulated period of time or until a stipulated relation is reached between material and atmosphere.
Conduit
Metal pipes used to contain electrical wiring in outdoor settings.
Conifer
A type of tree that’s characterized by needle-like or scale foliage, usually evergreen; tree that is a gymnosperm, which comes with cones and needle-like shaped or scale-like leaves, producing wood known commercially as softwood.
Contour Cutting
A flexible blade is necessary for contour cutting and for fairly wide curves the clumsy but efficient wooden bow to turning saw.
Conservation
Improvement, protecting, and wise use of natural resources according to principles that will assure utilization of the resource to obtain the highest economic and/or social benefits.
Consistency
The property of a liquid adhesive by virtue of which it tends to resist deformation.
Construction Lumber
Lumber that is suitable for ordinary and light construction.
Contact Angle
The angle between a substrate plane and the free surface of a liquid droplet at the line of contact with the substrate.
Convex
An outward-curving shape.
Cooperage
Containers consisting of two round heads and a body composed of staves held together with hoops, such as barrels and kegs.
Slack Cooperage: Used as containers for dry, semidry, and solid products. The staves are usually not closely fitted and are held together with headed steel, wire, or wood hoops.
Tight Cooperage: Used as containers for liquids, semisolids, or heavy solids. Staves are well fitted and held tightly with cooperage-grade steel hoops.
Copolymer
Substance obtained when two or more types of monomers polymerize.
Cope-and-Stick Joint
A method of construction raised panel doors where the tongues of the rails (horizontal) connect to the grooves of the stiles (vertical).
Corbel
A projection from the face of a wall or column supporting a weight.
Cord
A unit of measure often used for firewood stacked 4’ long x 4’ high x 8’ long.
Core Stock
A solid or discontinuous center ply used in panel-type glued structures, such as furniture panels and solid or hollow-core doors.
Corner
The line formed by the intersection of any two surfaces of a piece of lumber; not to be confused with ‘edge’.
Cost and Freight (CF)
Waterborne shipments to indicate that all loading charges and freight to final destinations are paid by the seller.
Cost, Insurance and Freight
In addition to paying all the loading charges and freight to final destination, the seller pay insurance costs.
Countersink
A tool that allows you to drill a hole so that the head of a screw will sit flush with the face of a board.
Coupling Agent
A molecule with different or like functional groups that is capable of reacting with surface molecules of two different substances, thereby chemically bridging the substances.
Covalent Bond
A chemical bond that results when electrons are shared by two atomic nuclei.
Crack
A large radial check resulting from greater tangential than radial shrinkage.
Creep
A time-dependent deformation of a wood member or adhesive joint due to sustained stress.
Crook
A lumber defect where an edgewise warp effects the straightness of the board.
Crossbands
In plywood with more than three piles, the veneers immediately beneath the faces, having grain direction perpendicular to that of the faces.
Cross Arms
Designed to serve as the horizontal cross member of utility poles, generally rough sawn full, sizes range from 3”x4” to 4”x6” by 8’ long.
Cross Breaks
Transverse planes of failure in tension parallel to the grain, caused by localized abnormal longitudinal shrinkage restrained by adjacent normal wood.
Cross Cut (crosscutting)
A cut made perpendicular to the grain of a board.
Cross Grain
The deviation of grain direction from the longitudinal axis of a piece of wood or from the stem axis in a tree. Pronounced deviation from the surface, especially in veneer, is termed short grain.
Crotch
In lumber, this refers to a piece of wood taken from the fork of a tree. Crotch veneer is highly valued for its figuring.
Crotch Grain
A figure produced by cutting centrally through a tree crotch in the common plane of both branches.
Crow Bar
A straight bar of iron or steel, with the working end shaped like a chisel and often slightly bent and forked; used as a lever.
Crown
Upper part of a tree, including branches and foliage.
Crown Class
All trees in a stand whose tops and crowns occupy a similar position in the canopy or crown cover. The class into which the trees forming the crop or stand may be divided is on the basis of both their crown development and crown position relative to the crowns of adjacent trees and the general canopy.
Crown Cover
Ground area covered by a crown; as delimited by the vertical projection of its outermost perimeter.
Crown Density
Thickness, both spatially (depth) and in closeness of growth (compactness) of an individual crown as measured by its shade density. Collectively, crown density should properly be termed canopy density, as distinct from canopy cover.
Crown Height
Vertical distance of a standing tree from ground level to the base of the crown, measured to the lowest live branch whorl or to the lowest live branch (excluding epicormics), or to a point halfway between the two.
Crown Length
Vertical distance of a standing tree from the top of the leader to the base of the crown, measured to the lowest live branch whorl or to the lowest live branch (excluding epicormics), or to a point of halfway between the two.
Crown Length Ratio
Of a standing tree, the ratio of a crown length to a tree height.
Crown Thinning
Removing superfluous live growth in a tree crown to admit light, lessen wind resistance, and reduce weight.
CS
Caulking Seam
CSG
Casing
Cubic Scale
Estimate of the cubic-foot volume of wood fiber in a log, tree, or other wood products.
Cumaru
Color varies from golden tan to a reddish brown
Difficult to saw
High density
Very durable
Used for outdoor decking, flooring, heavy construction, railroad crossties, tool handles, and turnery
Cup
A defect in the lumber where the face of the board warps up like the letter “U”.
Cup Shake
A split caused by lack of cohesion between the annual rings.
Cure
The change in properties of an adhesive by chemical reaction and thereby develop maximum strength. This is generally accomplished by the action of hear or a catalyst, with or without pressure.
Curing
The setting of an adhesive by chemical reaction. Also, the drying of wood, though this is not the preferred usage.
Curl
A term to describe what happens to wood as it grows. Curly wood looks like sand on the beach or river bottom with repeated ripples in the grain. The grain goes up and down causing the unusual look in the wood. This is also called “Fiddleback” or “tiger” grain.
Curly Cherry
Heartwood varies from rich red to reddish-brown
Fine, straight grain
Smooth texture
Medium strength
Good bending characteristics
Low stiffness
Medium shock resistance
Works easily with hand and power tools
Used for furniture, flooring, high-class joinery, boat interiors, tobacco pipes, paneling, and veneers
Curly Hard Maple
Creamy-white with red tinge
Usually straight grain
High bending and crushing strength
Medium stiffness
Used for furniture, heavy-duty, flooring, piano actions, and paneling
Curly Soft Maple
Creamy-white color
Wavy or “curly” grain
Medium bending and crushing strength
Low stiffness and resistance to shock loads
Used for furniture, joinery, domestic flooring, sporting goods and paneling
Curtain Coating
Applying liquid adhesive to an adherent by passing the adherent under a thing curtain of liquid falling by gravity or pressure
Custom Drying
Drying other people’s lumber
Custom Milling
Surfacing or remanufacturing other peoples lumber on order.
Customer Sawing
Sawing of lumber under contract, usually to given specifications.
Cut Stock
Clear pieces that have been ripped and cross cut from ship type lumber, such as stiles, rails, muntins, window sash, intended for further manufacture.
Cut-Full Lumber
Lumber intentionally manufactured in larger than normal thickness and width, usually to allow for shrinkage; a term sometimes confused with “full cut” lumber.
Cuttings
When using hardwoods, portions of a board or plank having the quality required by a specific grade or for a particular use.
