Peterson Portable Sawmills

Glossary L – P

A-C   D-G   H-K   L   M   N   O   P   Q-S   T-Z

L

Load
Measurement term for log and lumber volume: 40 cubic feet of logs equals 1.13 cubic meters, and 50 cubic feet of lumber equals 1.416 cubic meters.

Log
Eight-foot or longer tree segment; Length of tree suitable for processing into lumber, veneer, or other wood products; To harvest trees on an area.

Log deck
Pile of logs on a woods landing or in a mill yard.

Logger
A person employed in the production of logs and/or wood from standing timber. Also known as a lumberjack.

Logging truck
Vehicle used to transport logs. A logging truck consists of a cab, containing the engine and a place for the driver to sit, and a trailer on which logs are placed. The trailer usually has an adjustable carriage in order to accommodate loads of various lengths.

Log face
The exposed portion of the log, once bark has been removed.

Log jack
Tool used to raise a log from the ground during bucking; Similar to a peavey, but with a flattened steel loop on the underside so when the hook fastens into a log on the ground and the handle is lowered, the log is jacked up and remains elevated on the jack.

Log rule
Table intended to show amounts of lumber that may be sawed from logs of different sizes under various assumed conditions.

Log scale
Determines the value of a log by estimating number of board feet of lumber it will yield (less allowances for bark, slab and kerf).

Long butt
Section cut from the bottom log of a tree and culled because of rot or other defect; to cut such a section from a log.

Lumber
The product of the saw and planing mill for which manufacturing is limited to sawing, resawing, passing lengthwise through a standard paning machine, crosscutting to length, and matching. Lumber is simply solid wood that has been sawn to a particular size. Traditionally produced from very large diameter logs, lumber is now often made from logs as small as 8 to 12 inches (20 to 30 cm) in diameter. Lumber is always measured, bought, and sold based on nominal, rather than actual, sizes. Measurements are affected by moisture content and, in the case of hardwoods, by whether boards are surfaced or unsurfaced.

  • Board – lumber that is less than 38mm standard (2in. nominal) thickness and greater than 38mm standard (2in. nominal) width.
  • Dimension – lumber with a thickness from 38mm standard (2 in. nominal) up to but no including 114mm standard (5 in. nominal)and a width of greater than 38mm standard (2 in. nominal).
  • Dressed size – Dimensions after being surfaced with a planing machine. The dressed size is usually ½ – ¾ in. less than the nominal or rough size.
  • Factory and shop lumber – lumber intended to be cut up for use in further manufacture. It is graded on the percentage of the area that will produce a limited number of cuttings of a specified minimum size and quality.
  • Nominal size – As applied to timber or lumber, the size of which it is known and sold in the market (often differs from the actual size).
  • Rough lumber – lumber that has not been dressed (surfaced) but has been sawed, edges, and trimmed.
  • Shipping-dry lumber – lumber that is partially dried to prevent stain and mold in transit.
  • Side lumber – a board from the outer portion of the log – ordinarily one produced when squaring off a log for a tie or timber.
  • Structural lumber – lumber that is intended for use where allowable properties are required. The grading is based on the strength of stiffness of the piece as related to anticipated uses.
  • Timbers – lumber that is standard 114mm (nominal 5 in.) or more in least dimension. Timbers may be used as beams, stringers, posts, caps, sills, girders, or purlins.
  • Yard lumber – lumber of all sizes and patterns that is intended for general building purposed having no design property requirements.

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M

MBF
One thousand board feet.

Mill residues
Wood materials (coarse and fine) and bark generated at manufacturing plants (primary wood-using mills) when roundwood products are processed into primary wood products, includes slabs, edgings, trimmings, sawdust, veneer clippings and cores, and pulp screenings. (Note: Includes mill residues recycled as byproducts as well as those left unutilized and disposed of as waste.)

Moisture content
Amount of the water within a piece of lumber measured as a percentage of the weight of the dry wood. Typical moisture content for kiln dried construction lumber is 15%. Wood absorbs or gives off moisture depending on the ambient moisture in the air. The percentage of wood that is not moisture is referred to as ‘dry solids’. The moisture content must be specified by the buyer and agreed to by the seller; a 10% moisture content/90% dry solids specification is common.

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N

O

Old growth
Timber in or from a mature, naturally established forest that is beyond its peak growing period. Due to active competition with their companions for sunlight and moisture, this timber is usually straight and relatively free of knots.

One-point lowering system
On all ASM and WPF frames, the system allows the operator to lower all four corners of the mill equally from one position (also ‘one-point sizing’).

Overrun
Difference between the log scale of a shipment of timber and the volume of actual lumber obtained from it.

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P

Pallet
A low wood or metal platform on which material can be stacked to facilitate mechanical handling, moving, and storage.

Pith
The small, soft core occurring near the centre of a tree trunk, branch, twig or log, around which the annual rings form.

Planer
A piece of sawmill equipment that planes rough lumber, leaving it smooth and uniform in size.

Planer mill
Although sometimes a separate facility, the planer mill is usually tat part of a sawmill where lumber is planed, graded and sorted.

Plank
A broad, thick board laid with its wide dimension horizontal and used as a bearing surface.

Post
Timber with the larger dimension not more than 51mm (2 in.) greater than the smaller dimension and usually graded for use as a column.