Peterson Portable Sawmills

Glossary A – C

A   B   C   D-G   H-K   L-P   Q-S   T-Z


An area of land containing 43,560 square feet or 10 square chains. A square acre would be about 209 feet by 209 feet. A circular acre would have a radius of 117.75 feet.

Air dried
Lumber or other wood products that have been either dried by exposure to natural atmospheric conditions outdoors or in an unheated shed or died to equilibrium with the surrounding atmosphere. Moisture content of air-dried wood fiber depends on relative humidity, temperature, and length of drying period. Also referred to as air seasoned and contracts with kiln-dried lumber.


Using the left side of the blade when in the horizontal position to obtain large beams by the process of double cutting.

Band sawmill
An sawmill technology that uses a thinner band saw blade. A bandsaw also has teeth on both sides that allows cuts to be made in two directions.

The outer protective layer of the tree. Severely damaged bark in a tree is a defect that can lower the value of its logs. At the sawmill, logs are first debarked, then slabs are cut off leaving a rectangular or square cant to be cut into lumber.

Bark pocket
An opening between annual growth rings that contains bark. Bark pockets appear as dark streaks on radial surfaces and as rounded areas on tangential surfaces.

Any framing member placed to support a load. Also called a girder.

Bevelled Siding
See Weatherboards.

Blow down
Tree or trees felled by wind. Also know as wind fall.

A piece of lumber that is less than 38mm (2 in. nominal) in smaller dimension.

Board foot
Unit of measurement represented by a 1’ by 12’ by 12’ board for lumber and saw logs. The number of board feet in a log is estimated using one of three log scales: Scribner, Doyle, or International Rule. The actual yield of a log after sawn into lumber is often greater than the estimated yield. Both logs and lumber are sold by the thousand board feet (MBF).

Bole wood
The lower section of the trunk of a tree from the ground to the first limb or branch, that is of substantial diameter – roughly capable of yielding saw timber, veneer logs, or large poles. Seedlings, saplings and small-diameter trees have stems, not boles.

A short section of a tree trunk.

A lumber defect referring to deviation from a straight line drawn end to end along the wide face of a piece of lumber.

Boxed heart
The term used when the pith falls entirely within the four faces of a piece of wood anywhere in its length. Also boxed pith.

To saw a felled tree into short cuts; to saw felled trees into shorter lengths.

Cross beam on which logs rest in a trailer or a truck. The cross member on a log hauling truck, trailer, or log car on which the log rests. Also known as a bolster.

Swirl or twist in wood grain usually occurring near a knot, valued as the source of highly-figured burn veneers used for ornamental purposes.

Base of a tree; large end of a log.

Butt log
First log cut above the stump. Also known as butt cut.

Butt off
To cut off a piece of a log because of a defect; To square the end of a log.

Ridge of wood that develops in the angle between a lateral root and the butt of a tree, which may extend up the stem to a considerable height.

Butt rot
Decay or rot characteristically confined to the base or lower bole of a tree.

Primary wood products (e.g. pulp chips, animal bedding, fuelwood, etc.) recycled from mill residues.

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Wire rope used for lines in yarding systems.

Cable logging
Yarding system employing winches in a fixed position.

Cable yarding
Taking logs from the stump area to a landing using an overhead system of winch-driven cables to which logs are attached with chokers.

Instrument for determining tree and log diameters by measuring their rectangular projection on a straight graduated rule via two arms at right angles to (and one of them sliding along) the rule itself; The optical caliper determines upper, out-of-reach tree diameters through an optical system incorporating two parallel lines of sight separated by a variable baseline.

A thin layer of tissue between the bark and wood that repeatedly subdivides to form new wood and bark cells.

Log that is squared on two or more sides and to be sawn further. Ordinarily, cants are intended for researing at right angles to their widest sawn face. A log is first debarked then the rounded slab or outside portion of the log is cut off by the sawyer.

Cant hook
A pole with a movable hooked arm at or near one end, used for catching hold of logs and rolling them. Differs from a peavey in that it has no spike in the end of the stock.

The sawmill device on which a debarked log is placed which moves the log back and forth through the saw blade creating slabs, cants and lumber. The log is also turned on the carriage before making the next cut.

Small piece of wood used to make pulp. Chips are made either from wood waste in a sawmill or pulpwood operation, or from pulpwood specifically cut for this purpose. Chips are larger and coarser than sawdust.

Short length of flexible wire, rope, or chain used to attach logs to a winch line or directly to a tractor.

Circular sawmill
The traditional sawmill uses a circular saw (large version of a hand held power saw). Circular saws are thicker (larger kerf) than band saws and produce more sawdust. Logs can be cut moving on the carriage in only one direction, then the carriage returns and turns the log for the next cut.

Compression wood
Abnormal wood formed on the lower side of branches and inclined trunks of softwood trees. It is identified by its relatively wide annual rings, relatively large amount of latewood, and lack of demarcation between earlywood and latewood in the same annual rings. Compression wood usually shrinks excessively longitudinally, compared with normal wood.

Conditioning (pre and post)
The exposure of a material to the influences of a prescribed atmosphere for a stipulated period of time or until a stipulated relation is reached between material and atmosphere.

Tree that is a gymnosperm, usually evergreen, with cones and needle-shaped or scale like leaves, producing wood known commercially as softwood.

Contract hauler
Independent truck owner or a driver working for the contractor who hauls logs from the woods to the dump.

Contract logging
Operator doing all or part of the logging for a company; Independent logger who logs standing timber according to the terms of a contract.

Person who has a contract to do all or any part of a logging job.

Stacks of hardwood 4’ high by 4’ wide by 8’ long. It is the measure by which firewood is customarily sold, sawdust is sometimes sold, and small diameter logs sometimes bought. One cord is the equivalent of 129 cubic feet, 4.7 cubic yards.

Cross cut
Wood cut across the grain; to cut a piece of lumber perpendicular to its length.

The live branches and foliage of a tree.