| Term | Description |
| Log trailer | Built with permanent stakes to carry sawlogs or pulp logs. Log trailers may have a grapple loader mounted front or rear in which case the operator can load himself. The increased cost of a loader on a log trailer means the trucker’s rate will likely be much more. Without a loader, the logger must use his equipment to load the log trailer. |
| Longitudinal | Generally parallel to the direction of the wood fibres. |
| LOSP | Light organic solvent preservative. A wood preservative. |
| Lumber | A wood product manufactured from a log and sawn on all four sides. |
| Lumber | A North American synonym for timber. |
| Lumber | Logs which have been sawn, planed, and cut to length. |
| Lumber | 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. A variety of equipment is used to produce lumber. Newer mills that process softwood logs combine scanners, computers to calculate optimium sawing sequences, and high speed, thin-kerf saws designed to obtain maximum lumber yield. The newest “lumber” products are not lumber at all in the traditional sense, but composite products created from veneers, thin flakes, or other materials such as plastic. Such products have more uniform strength properties than solid-sawn wood and can be made to large sizes even when using small trees as raw material. 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. Also see Yield. |
| Lumber ruler | A tool resembling a ruler with a handle at one end and a hood at the other which is used to calculate the board footage of a piece of lumber. |
| Lumber-Core Plywood | Plywood where thin sheets of veneer are glued to a core of narrow boards. Lumber-core plywood differs from regular plywood in that regular plywood is made up of successive layers of alternating grain veneer. |
| Luster | The property of wood that enables it to reflect light. It depends partly on the angle at which the light strikes the surface and the type of cells exposed on that surface. |
| LVL | Laminated veneer lumber. |
| Lyctid borer | a wood borer, sometimes known as the powder post borer, that can attack some hardwoods. |
| Lyctid susceptibility | Timber is classified according to its susceptibility to attack by lyctid borer. Legislation governs the sale and use of lyctid susceptible timber in NSW and Queensland; Australian Standards limit the use of lyctid susceptible sapwood throughout Australia. |
| Market pulp | White pulp from hardwood trees that is dried into thick blotter-like sheets and baled for shipment to a paper mill for repulping to make paper products. |
| Marquetry | Decorative inlay and veneer work. |
| Maximum Crushing Strength | A measure of the ability of a piece of wood to withstand loads in compression parallel to the grain up to the point of failure. |
| MBF | See thousand board feet. |
| Mechanically laminated timber | Laminated timber where the laminations are joined with mechanical fasteners. |
| Medium Density Fiberboard (MDF) | A panel product manufactured from wood fibers combined with a synthetic resin or other suitable binder. The panels are manufactured by the application of heat and pressure by a process in which the inter-fiber bond is created primarily by the added binder. The typical density range for MDF is 31-50 lbs/cubic ft. |
| Medium density fiberboard (MDF) | A special type of tempered hardboard characterized by a very fine, smooth finish. MDF is used in cabinet making. |
| Medium density fibreboard (MDF) | A panel product manufactured from ligno-cellulosic fibres combined with a synthetic resin or other suitable binder. |
| Medium-Density Fiberboard (MDF) | A panel product manufactured from ligno-cellulosic fibers combined with a synthetic resin or other suitable binder. The panels are manufactured to a density of 31 pounds per cubic foot (0.50 specific gravity) to 55 pounds per cubic feet (0.88 specific gravity) by the application of heat and pressure by a process in which the interfiber bond is substantially created by the binder. Other materials may have been added in the manufacturing process to improve certain properties. |
| Merchantable timber | A tree or stand that has attained sufficient size, quality and/or volume to make it suitable for harvesting. |
| Mill chips | After debarking and before a sawmill cuts lumber, it saws off the outer four slabs to reduce the log to a square or rectangular cant. The slabs are mostly the sapwood portion of the log and may be resawn to save low quality boards (e.G., Pallet boards), or the slabs are sent to the chipper. Most chippers pass their chips over a two-deck vibrating screen to separate the “overs,” “accepts” and “fines.” The “overs” are re-circulated through the chipper again and the “fines and sawdust” are blown into their own pile. The chip “accepts” are blown into a chip van trailer, blown into a pile on the ground to be loaded over the top of an open top trailer with a front-end bucket loader, or they are conveyed into an overhead bin which drops chips into an open top trailer. |
| Millwork | Building materials made of finished wood that have been specially manufactured by a plant or mill. Millwork includes molding and trim, doors and windows and their frames, staircases, cabinets, and other specialty items. |
| Minimum weight | The minimum weight that will be charged for, regardless of the weight being hauled. |
| Miter gauge � | A tool that slides in a slot on a power tool such as a table saw, router table, bandsaw, etc. A miter gauge can be adjusted to different angles and is used to slide the stock past the blade. |
| Miter-and-spline joint | A joint with two mitered surfaces connected by a spline. (See spline) |
| MMBF | A million board feet. |
| Modulus of Rupture (MOR) | The maximum load that can be applied, in bending, to a member before it fails. |
| Moisture content | The weight of moisture contained in a piece of timber expressed as a percentage of the oven dry weight. |
| Moisture Content | A measure of the amount of water in a piece of lumber. |
| Moisture Content | Weight 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,” that is, dried construction lumber would be 85% dry solids. Product standards for lumber manufactured in the United States are developed under the jurisdiction of the U.S. Department of Commerce and administered by the American Lumber Standards Committee (ALSC). Members of the ALSC are representatives of various softwood lumber trade associations. As specified in the ALSC American Softwood Lumber Standard, softwood lumber is sold as “dry” if at a moisture content of 19% or less. Most hardwoods manufactured in the United States are produced to standards developed by the National Hardwood Lumber Association (NHLA). No single moisture content, however, is specified for hardwoods because the uses are more specialized. The moisture content must be specified by the buyer and agreed to by the seller; a 10% moisture content specification is common. |
| Moisture Content (MC) | The weight of moisture in wood or the amount of water contained in wood, usually expressed as a percentage of the weight of the ovendry wood. |
| Moisture gradient | A progressive decrease (or increase) in moisture content between the core and the surface of a piece of wood. |
| Molding | A trim piece of millwork used either strictly for decoration or for both decoration and to finsih a joint. |
| Mortice and tenon joint | A joint where a hole or slot known as a mortice (a) is formed in a piece of timber to receive the reduced end of similar size or tenon (b) from another piece. The joint is often secured with wedges, dowels or steel plates. |
| Mortise | A rectangular hole cut into a piece of wood to accept a tenon. (See tenon) |
| Mortise and Tenon joint | A joinery technique where the tenon from one board fits into the mortise of another. |
| Movement | The extent of expansion and contraction which occurs with dried wood as its moisture content responds to changes in relative humidity in service. |
| Movement in Service | The changes in dimensions that accompany the usual fluctuations of relative humidity and temperature after wood is placed in service. It reflects the sum of the percentage of shrinkage in the tangential and radial directions in response to a change in relative humidity from 90 to 60 percent at room temperature. The classification below is from Tropical Timbers of the World, USDA Agric. Handbook No. 607.
Classification Percent Movement |
| Mud Season | The period of weeks between winter and spring or summer and fall when the ground in a forest is largely mud, thawing or freezing between warmer days and colder nights. During mud season, heavy logging equipment is not permitted in the woods nor are trees cut during this time. Industry professionals that depend on a continuous supply of logs must account for these seasons and stockpile sufficient quantities to process during mud season. Truckers are usually available during mud season to haul logs from distant concentration yards which may have accumulated logs for mud season. |
| Nail | A sharpened piece of metal or plastic driven into timber to fasten a joint. |
| Nail gun | A hand-operated tool powered by compressed air which drives nails. |
| Nail plate connector | Sheet metal plates stamped so that nails are formed on one side and pressed into timber to make a joint. |
| Nail ring | A generally rectangular pattern of nails used to join timber elements. |
| Net terms | The total amount of an invoice that is due if the discount is not taken. |
| Net� | net A futures market invoicing term meaning that no cash discount is given for prompt payment. |
| Nominal | The name for the size of a piece of lumber, not the actual measurement of that piece (i.E., What we call a 2×4 is actually a piece of lumber measuring 1 1�2� x 3 1�2�). |
| Nominal Size | The rough-sawn size of a piece of lumber. When purchasing planed lumber it is sold by its nominal, rough-sawn, size. For example a 2″x4″ is the nominal size for a board whose actual dimension is 1.4″ X 3.25″. |
| Non-piloted bit | A router bit without a guide bearing. (See piloted bit) |
| nosing | The rounded front edge of a stair tread that extends over the riser. |
| Off grade | Lumber that does not conform to the grade it was represented as being. |
| Off the market | A trading term meaning that a seller is not currently soliciting business. |
| Ogee | A decorative molding profile with a S shape. |
| Old growth | A forest of mature or over mature timber that is beyond its peak growing period. |
| Old Growth (Virgin Timber) | Old, naturally established trees often characterized by dense straight grain and a lack of knots and defects. |
| On hand | A rolling unsold railcar that has stopped at a diversion point pending further orders from the shipper. |
| Open Coat | A piece of sandpaper with abrasive particles that are spread out to prevent clogging. See also closed coat. |
| Open grained | Common classification for woods with large pores in the grain. Also known as coarse textured. |
| Oriented strand board (OSB) | Structural panels made of narrow strands of fiber that are oriented lengthwise and crosswise in layers and bound together with resin. Depending on the resin used, OSB can be suitable or interior or exterior applications. Plywood and OSB are also referred to as structural panels and used in applications where strength and stiffness are required, e.G., Roofs, walls, floors, etc. |
| Outfeed | The side of a power tool where the board exits. (See infeed) |
| Oven-dried weight | The weight of a piece of lumber that has been dried, under high temperatures, in an oven until it is devoid of all water. |
| Ovendry Weight | Weight obtained by drying wood in an oven at 102 degrees F. (plus or minus 3 degrees F) until there is no more weight loss. |
| Ovendry Wood | Wood that has been dried to its ovendry weight. |
| Overstorey | That portion of the trees, in a forest of more than one storey, forming the upper or uppermost canopy layer. |
| Pallet | A low wood platform on which material can be stacked to facilitate mechanical handling, moving, and storage. |
| Paper wrap (PW) | Heavy paper, wrapped around the top and four sides of a unit of lumbr, to protect it during transit and outside storage. Often a condition of sale. |
| Paperboard | Grades of paper whose thickness is more than 0.012 inches and which are heavier and more rigid than ordinary paper. |
| Parabolic arch | An arch whose curve is a parabola. |
| Parallel strand lumber (PSL) | A type of engineered wood product. |