A simple and accessible tool for understanding the fundamental terms related to wood. From the meaning of sapwood and heartwood to the characteristics of texture, grain, and density. A useful resource for professionals, citizens, and students who want to familiarize themselves with the language of the sector.
Gluing in which the adhesive (or glue mixture) is applied discontinuously and only to certain points of the workpiece.
Procedure for a surface treatment in which impregnating agent is applied to wood by spraying.
Treatment in which appropriate steamers are used to apply a preservative to wood.
Method of distributing water or other liquid by sprinkling. This is generally adopted to keep the moisture content of stacked timber high.
Amount of adhesive (adhesive mixture) per unit area applied to an adherend (e.g., in grams per square meter (g/mý)). Such amount may be applied to only one of the surfaces (and in that case, in the plywood industry, it is referred to as ” spread degree per single glueline”) or to both (and in that case it is referred to as “double glueline”).
Small-sized branch.
Area of the stem from which the lower branches originate.
Deformation in the lengthwise direction, occurring in a plane orthogonal to the edge of a semi-finished product. In the case of a sawn timber, it is generally due to the presence of reaction wood along one of its longitudinal edges or to internal stress.
Tendency of compressed wood to partially recover, due to a springback phenomenon, its original state prior to compression.
Variation in the shape of a woody material (mostly a trunk or its slab/siding or trimmings) which occurs immediately after the passage of the blade during the sawing process. It is usually caused by the presence of internal tensions.
Of a saw blade or tooth, in which the kerf was obtained by bending the teeth alternately to one side and the other. Note: The operation is carried out with either a lathing paddle or a lathing anvil.
A device for decreasing the friction of the cutting chain on the bar tip of chainsaws. It consists of a star-shaped spool on a roller bearing.
Ability to issue offshoots and subsequent coppice shoot formation by stumps as a result of one or more silvicultural operations.
Rectangular cross-sectional sawn timber with wane (if permissible) not exceeding the permissible limit.
See “foot”.
Ray cell elongated in axial direction. Note: Cells of this type compose some uniseriate rays and parts, typically the margins, of some multiseriate rays.
Timber that has been given a prismatic shape by special processing to obtain flat surfaces.
Timber processed by sawing or otherwise, in such a way that its cross-section is square or with slightly different cross-sectional dimensions. A freshly squared log may still be called a ‘squared log’ although squared timbers are currently referred to as ‘beams’. The term is also used to refer only to timber ‘squared with an axe’ (= ‘axed truss’) or, more modernly, processed with squaring-chipping machines from which a result similar to processing with an axe is obtained, i.e. a squaring with wane tolerance that more or less follows the tapering of the trunk. Among the types of ‘travame asciato’ on the market in Italy we distinguish: (a) “Uso Trieste”, squared on four almost parallel faces up to about 1/3 of the length and further on squared following the tapering of the trunk; (b) “Uso Cadore”, squared following the tapering along the whole length; (c) “Uso Fiume”, with parallel sides along the entire length.
See “standard deviation”.
Sawn timber of coniferous trees with parallel edges of a length in any case not less than 4 m and a rectangular cross-section with dimensions approximately in a ratio of 1:2 which, according to UNI standards, may range from 8 by 16 to 12 by 28 cm.
End oriented at right angle to the axis of the woody element and having a flat surface.
Operation to regularize the edges of wood-based panels after pressing (making them two by two parallel) and to obtain their final dimensions. Cuts are made generally by pairs of circular saws operating along perpendicular directions. The term therefore also indicates the condition of parallelism between opposite edges and perpendicularity (90° angle) between adjacent edges of a panel or semi-finished product. In the plywood standard it is measured over one meter of edge length.
Pile, more or less regular in shape, of certain woody assortments awaiting later use or processing.
Volume of a woodpile that is measured based on its external dimensions, and therefore it includes the air spaces within the woodpile. The German term “Raummeter” (rm) is not recommended.
Worker or machine employed to arrange wood in stacks or to load it onto vehicles.
Arrangement of wood or timber in piles of more or less regular shape awaiting subsequent handling. In some cases it is a stage in the processing.
Part of an operation. It is normally the smallest unit of the work. In detailed studies, it can be divided into “time elements”.
Stacking without laths in which a certain amount of aeration is still provided by a staggered arrangement of boards. It is an intermediate stacking mode between bulk stacking and open stacking with laths. It is suitable for sufficiently dry timber.
Any alteration in the natural color of wood not caused by drying, but due to artificial causes from the application of dyes or natural causes such as exposure to weather, chemical interactions, fungal attack, etc. Color alteration may be due to: – water: yellowish to blackish coloration that develops on the surface of light-colored lumber when it is in contact with water during immersion or seasoning; – exposure to weathering; – wounds; – fungi: color alteration (blue and gray in color) without tissue destruction, due to the development of certain fungi that feed on the cellular contents but do not cause wood decay; – contact with laths: bluish or gray discoloration that develops, during seasoning, on boards at the point of contact with sticker alignment.
See “stain”.
See “mordant”.
Veneer that shows stains caused by external factors (such as mould, excessive exposure to light, grease, etc).
Round wood of small diameter, usually sharp at one end.
A document, consensual and approved by a recognized body, which provides, for common and repeated use, rules, guidelines or characteristics, relating to certain activities or their results in order to achieve the best order in a given context.
Also called “mean square deviation,” it is an index of variability of data in a population given by the average deviation of the data from the arithmetic mean of the population. It is the square root of the mean of the squares of the deviations (i.e., variance).
An estimate of the degree a particular statistical quantity, such as the mean, derived from sampling a population, may vary from the “true” value (expected value) based on the entire population or statistical universe.
Technical standards formulation, dissemination and application reference activities.
See “coppice”.
Dead tree that maintains its upright position on the ground.
In plywood, staples applied with a special stapler both to repair edge splits in a ply and to allow a more stable juxtaposition between adjacent plies during panel composition.
Set of radial cracks starting from the pith (or heart) of a trunk, visible on its cross-section.
Set of two or more radial cracks on the end grain. The German term “Kernriá” is used only if there is only one pair.
A poorly glued joint caused by too insufficient layer of glue, too much pressure, or poor glue viscosity that caused the glue to ooze out during the setting period.
State of an artefact in relation to the modifications and degradation it has undergone.
The state of the art represents a snapshot of the current situation with respect to the level of development or technical knowledge reached so far.
Provision that provides a piece of information.
Circumscribed area that represents a complete and defined set of ecological conditions ( which in some way are capable of influencing tree growth), to which reference is made during the stationary survey phase.
(1) Piece of sawn wood or wood worked by splitting that forms one of the uprights of a barrel or any fustame article. (2) Piece of wood already processed by sawing or splitting, intended to be further processed and assembled to form fustame articles. A distinction is made between liquid fustame staves and solid fustame staves. Note: According to AFNOR standards, French “merrain” is processed by splitting and has rectangular dimensions with thickness from 18 to 35 mm and width from 40 to 120 mm. Similar case goods are rather packing boards. The term “stave” is also improperly used to refer to floor boards.
Measurement of the capacity of a wall or floor to reduce noise transmission.
A naturally circulating kiln in which relative humidity is controlled by steam jets that also cause faster air circulation compared to that which would occur by simple convection.
Treatment (incorrectly called “evaporation”) sometimes performed on log or semi-finished products for one or more of the following reasons: – to facilitate subsequent processing (e.g. rotary cutting); – to dilute the cellular contents attractive to biodegradation agents; – to modify (darken) the natural colour of the wood; – regularise or reduce any colour differences between the sapwood and heartwood portions; – reduce or regularise any moisture gradients between the internal portions and the surface of the assortments concerned. Steaming consists in the use of special cells or vats inside which, after inserting the workpieces for treatment, hot water or saturated steam is injected for a sufficient time to achieve the envisaged objectives. The duration of the treatment depends on various parameters such as, for example, the wood species, the size of the pieces, and the temperature.
Prolonged immersion of timber in hot water, such as when preparing a log or trunk for rotary cutting. Note: A steeping is used to clean the timber of anything that might damage sawing tools.
Registered trademark of Deloro Stellite Inc. for a specific type of cobalt-based alloy used to reinforce (i.e. increase hardness) the cutting edges of blades and other surfaces of industrial equipment subject to wear.
Epigeal portion of a tree corresponding to its principal growth axis. In conifers it extends from the base of the tree to the vegetative apex, whereas in deciduous trees it extends from the base to the insertion of the main branching. Together with the roots and crown, it constitutes one of the three portions that characterize the morphology of a standing tree and particularly the one of greatest technological and commercial value.
Stack boards or other sawn timber in such a way that the longer pieces are at the bottom, making one or two sides of the stack have the appearance of a staircase.
Unit of stacked volume corresponding to a stack of wood with the dimensions of 1 x 1 x 1 m. It thus includes wood and voids. ([2])
Visible discoloration on the surface of a sawn timber caused by laths placed between sawn timbers.
The vertical arrangement of laths (one above the other) in a stack of timber for seasoning.
Notching or crushing of wood caused by laths when the load superimposed on them is too high compared to the load-bearing surface.
Localized color changes or marks under or near the bearing surface of the laths. Possible causes include: laths that are too wet or dirty (infected with mold, blue stain, or covered with dirt), delayed drying under laths, and chemical reactions between timber and laths.
Placement of strips of material, usually wooden laths of rectangular cross-section, between layers of sawn timber or panels forming a stack in order to facilitate air circulation and promote cooling, heating, or drying.
Roughly isodiametric cell with a strongly lignified secondary wall, often with obvious layering and which may contain branched pits, e.g., sclerotic tyloses.
Portion of the stem that has a greatly reduced diameter.
Closure element for bottles or narrow-mouth containers, which is generally introduced by pressure into the opening.
Long, thin strips or pieces of metal of a certain thickness (after precision machining) used at the edges of the plates of a press in order to ensure that a certain thickness is achieved during the pressing of shredded material.
Place where material storage takes place.
Period of time within which a packaged adhesive can be stored under specific temperature conditions while preserving its suitability for use.
Cambium characterized by horizontal serialization of initials.
Cells arranged in piles, seen in tangential plane.
Term used for axial cells and rays when arranged in horizontal series in the tangential plane. Note: The term is referred to particular tissues, e.g., “seriate parenchyma,” or used in a general sense, e.g., “wood with seriate structure.” The presence of seriate structure is the cause of the horizontal striations visible to the naked eye.
Crack parallel to an edge.
Unit change in the size or shape of a body from its original value caused by the application of a force. Theoretically it is a dimensionless quantity but in practice it is expressed in centimeters per centimeter.
Woody particle, resulting from a cut made with a knife, which has a determined thickness and length, parallel to the direction of the grain, at least double and generally equal to several times its width. It corresponds to a narrow “flake”.
Structural element of steel ropes, consisting of a set of elementary wires wound together.
Rope formed by one or more layers of steel wires wrapped around a central wire.
Tracheid of an axial series (row) of tracheids (or tracheids mixed with parenchymal cells). Each series originates from a single cambial initial.
Characteristic or quality of a wooden element that limits its load-bearing capacity.
External force, per unit area, that develops in resistance to a stress or, within certain conditions, that is internally self-generated as a result of the change in previous conditions of equilibrium, humidity, temperature, or combination thereof.
Qualification standards used for timber in which timber categories are established on the basis of the minimum required strength determined “by sight” (“visual grading”) or on the basis of mechanical tests. The whole operation is called ‘strength-based qualification’.
See “conditioning phase”.
Sawn timber whose surface appearance and/or performance characteristics have been judged and estimated by visual inspection or non-destructive testing and has been assigned a certain quality and/or strength class. Therefore, the classification can be made “according to appearance” or “according to mechanical strength”.
See “stressed skin board”.
Composite panel whose core is prepared in such a way that it leaves gaps and is therefore made of crossed strips of wood, layers of plywood arranged by knife and variously curved, or even layers of corrugated cardboard.
In a pallet, rectangular section element that distance the bottom deck from the top deck.
In a pallet, horizontal element placed perpendicular to the floor boards.
In the manufacture of cores for core plywood, it is the gluing for continuous strips narrower than the width of the pieces to be joined.
Processing stage consisting of partial debarking of a woody stem in two, three, or four opposite strips.
Parquet consisting of strips of equal width and random length.
See “stripe figured wood”.
Aesthetic effect due to different inclination of the grain in successive growths (interlocked grain). It appears on the surface of a sawn timber or sliced veneer as a series of bands of different luster, iridescent depending on the angle at which they receive light. Note: If very regular and present more or less along the entire length of the piece it is called ” stripe figure”; if irregular and discontinuous “interrupted stripe figure”.
Figure given by the grain of the wood appearing in parallel or nearly parallel lines (typical of cuts made “on the quarter”). According to another definition, the term is also used to refer to a veneer obtained by cutting along a direction slightly deviated from the radial direction in order to highlight a striped pattern but in which the ray traces do not appear too pronounced.