UPMSP Class 12 Wood Craft key terms

The inner, older wood of a tree trunk that no longer conducts sap. It is usually darker, denser and more durable than the outer wood because deposits block the pores.

The living outer layer of wood just beneath the bark that carries water and nutrients up the tree. It is lighter in colour, softer and more prone to insect and fungal attack.

The alignment of wood fibres along the length of a board. Planing, sawing and jointing are easier and give cleaner results when the tool moves with the grain, not against it.

Controlled drying of timber to reduce its moisture content so it becomes stable and strong. It may be done in the open air or in a heated kiln before the wood is used.

The amount of water held in wood, expressed as a percentage of its oven-dry weight. It is measured with a moisture meter and decides how much the wood will shrink or swell.

Seasoning timber inside a chamber where temperature, humidity and air movement are controlled. It dries wood faster than air drying and can kill insects, but needs careful scheduling to avoid checking.

The moisture level wood settles at when it is in balance with the surrounding air. Furniture timber is normally dried close to the humidity of the place where it will be used.

Treating timber with chemicals such as preservative salts or oils so that fungi, borers and termites cannot attack it. It is used mainly for timber exposed to damp or soil contact.

The larva of a beetle that tunnels through seasoned timber, leaving small round flight holes and fine dust. Infestation weakens the wood and must be treated before use.

Cutting a board along its length, parallel to the grain, usually on a table saw or with a ripsaw. It produces long strips and needs a riving knife to prevent kickback.

Cutting wood across the grain to shorten a board to length. It is done with a crosscut saw or a mitre saw and gives a shorter, more brittle cut face than ripping.

A small hand saw with a stiff back and fine teeth, used for accurate straight cuts such as tenons and shoulders. The reinforced spine keeps the blade rigid during controlled joinery work.

The angled cutting edge ground at the tip of a chisel, plane iron or knife. Its angle suits the job: about 25 degrees for paring and nearer 30 degrees for chopping.

Refining a sharpened edge on a fine stone or abrasive film to remove the burr and polish the bevel. It is the final stage that gives a chisel or plane iron a keen, lasting edge.

The total angle formed at the cutting tip of a tool edge. A smaller angle cuts more easily but dulls faster, so hardwoods and chopping work call for a larger angle.

Rough, splintered fibres left on a cut surface when the tool lifts the grain instead of slicing it cleanly. It happens when working against the grain or with a dull blade.

A machine with a circular blade protruding through a flat table, used for ripping and accurate dimensioning. The blade height and fence setting control the depth and width of cut.

The violent throwing back of a workpiece by a rotating blade when it binds or is pinched. It is prevented by a riving knife, correct fence alignment and never standing in line with the blade.

A simple wooden or plastic handle used to feed short or narrow stock past a machine blade. It keeps the operator's hands a safe distance from the cutting edge.

A strong frame joint in which a projecting tenon on one member fits into a matching rectangular mortise cut in the other. It is glued and often pinned for extra strength.

An interlocking corner joint made of flared pins and matching tails that resist pulling apart. It is used for drawers and boxes and is often left exposed as a decorative feature.

A corner joint where both pieces are cut at an angle, usually 45 degrees, so the joint runs diagonally across the corner. It is common in picture frames and mouldings.

A short cylindrical wooden pin inserted into matching holes to align and strengthen a joint. Glue on the dowel and inside the holes forms the bond.

A glue used to bond wood surfaces, such as PVA for interior work or resin glue for damp conditions. Surfaces must be clean, close-fitting and clamped until the glue sets.

A device that holds glued parts or workpieces firmly in position while the adhesive cures or while cutting. Sash clamps suit long frames and G-clamps suit small assemblies.

A drawing method that shows a three-dimensional object as separate flat views, such as front, top and side. Each view is drawn to the same scale and aligned with the others.

A pictorial drawing in which the three main axes are set 120 degrees apart, giving a three-dimensional view without perspective. It is useful for showing a finished project to a client.

A drawing in which every dimension is reduced or enlarged by a fixed ratio, such as 1:10. It lets a full project be planned on paper and read accurately by the maker.

A list that sets out every piece of timber, hardware and finish needed for a project, with sizes and quantities. It is used to cost the job and to order stock.

Working out the quantity of material, hardware and labour a job will need before work starts. A careful estimate prevents waste and allows a realistic price to be quoted.

The order of using progressively finer abrasive grits on a surface, for example 80, 120 then 180. Each grit removes the scratches of the previous one and leaves a smooth base for finish.

A paste used to fill small holes, cracks and open grain before finishing. It should be matched to the timber colour and sanded flush once hard.

A colouring liquid applied to bare timber to change its tone while leaving the grain visible. It is followed by a clear finish that protects the stained surface.

A high-gloss finish built up by rubbing shellac dissolved in alcohol onto the wood with a pad. It gives a deep shine but is less resistant to heat and water than modern lacquers.

A fast-drying clear coating that forms a hard protective film on wood. It is usually sprayed and gives good resistance to wear and moisture on furniture surfaces.

The safety gear worn by a worker, such as goggles, ear defenders, a dust mask and safety shoes. It is the last line of defence after machine guards and safe working methods.

A system of hoods, ducts and a fan or vacuum that captures wood dust at the machine before it reaches the air. It reduces fire risk and protects the lungs.

Fine airborne particles produced by sawing and sanding that can damage the lungs and, in high concentrations, ignite. Control relies on extraction, ventilation and a suitable mask.