NSSCO Woodwork 6190 flashcards
NSSCO Woodwork 6190 · Build recall with a focused review session.
32 cards. Read the term and the definition here. The deck at the top of this page is optional.
- Moisture content
- The mass of water in timber expressed as a percentage of its oven-dry mass. Interior timber is normally dried to about 10-15% to limit shrinkage and movement.
- Quarter sawing
- Sawing logs so growth rings meet the board face at a high angle. Produces straighter grain, less cupping and lower tangential shrinkage than plain sawing.
- Reaction wood
- Wood formed in leaning or bent trees: compression wood in softwoods and tension wood in hardwoods. It shrinks unevenly and distorts badly when machined or dried.
- MDF
- Medium density fibreboard, made from fine wood fibres bonded with resin and pressed. It has uniform density, machines and routes cleanly, but has weak edges and poor screw holding.
- PVA adhesive
- Polyvinyl acetate emulsion glue used for interior joinery. It sets by loss of water, gives strong close-fitting joints, and is not suitable for prolonged damp conditions unless cross-linked.
- Sanding sealer
- A thin, fast-drying finish applied before a topcoat. It raises and stiffens surface fibres, fills open pores and reduces the amount of finish absorbed by the timber.
- Cap iron function
- The chip breaker fitted over a plane iron. Set close to the cutting edge it breaks shavings and reduces tear-out on difficult or reversing grain.
- Rip saw teeth
- Saw teeth shaped like small chisels that cut along the grain. Rip saws have few teeth per inch, typically 4-7, and remove material quickly in long strokes.
- Marking gauge
- A tool with a stock and a spur or knife point used to scribe lines parallel to a face side or face edge. The stock is pressed against the reference face while marking.
- Router feed direction
- When edge routing by hand, feed the router left to right along an edge so the cutter turns against the feed. Feeding with rotation causes a dangerous climb cut.
- Riving knife
- A metal plate mounted behind a circular saw blade, rising and falling with it. It prevents the kerf closing and gripping the blade, reducing kickback risk.
- Surface planer purpose
- A machine that flattens one face and squares one edge of timber against a fence. These become the reference faces for later thicknessing and marking out.
- Thicknesser rule
- A thicknesser produces a face parallel to an existing flat face. A flat reference face must be planed first, otherwise the finished board copies the original distortion.
- Band saw blade width
- Narrow blades cut tight curves; wide blades track straighter and cut thicker stock. Blade width limits the minimum radius of cut that can be made.
- Mortise and tenon ratio
- A tenon is normally about one third the thickness of its rail, and the mortise about two thirds the rail width. These proportions balance strength against weakening the stile.
- Haunched tenon
- A tenon with a short extra section above the main tenon. It fills the groove in a stile, prevents the rail twisting and strengthens the joint near the top edge.
- Dovetail angle
- The slope of the dovetail sides, commonly about 1:6 in hardwood and 1:8 in softwood. Harder timber needs a stronger, more angled tail to resist pulling apart.
- Stile and rail
- The vertical members of a frame are stiles and the horizontal members are rails. In a door, the hanging stile carries the hinges and the lock rail holds the lock.
- Face side mark
- A symbol marked on the flattened reference face of a piece of timber. All subsequent squaring, gauging and machining is measured from this datum face.
- Board foot
- A volume of timber equal to 144 cubic inches, or a piece 1 inch thick, 12 inches wide and 12 inches long. Used in imperial timber pricing.
- Waste allowance
- Extra material added to a cutting list to cover saw kerfs, defects, machining and errors. Typically 10-15%, rising to 25-30% for short or figured stock.
- 3-4-5 method
- A setting-out check for a right angle using a triangle with sides in the ratio 3:4:5. Measuring 3 and 4 units along two lines gives 5 units across the diagonal when square.
- Roughing gouge
- A deep, U-shaped turning tool used to convert square stock to a cylinder between centres. It removes material quickly but is not used for fine detail.
- Bevel rubbing
- A turning technique where the bevel of the tool contacts the work behind the cutting edge. It stabilises the cut, controls depth and reduces catches.
- Faceplate turning
- Turning work mounted on a faceplate or chuck with the grain running across the lathe axis. Used for bowls, platters and hollow forms rather than spindles.
- Spokeshave
- A hand tool with a short sole and a cutting iron held between two handles. It shapes and fair curves such as chair legs and tool handles.
- Cutting list
- A table listing every component of a project with quantity, finished dimensions, material and notes. It is derived from the working drawings before any timber is cut.
- Isometric drawing
- A pictorial drawing with three axes at 120 degrees, showing height, width and depth without perspective. It communicates a design quickly but is not used for dimensioned manufacture.
- Costing formula
- Total cost equals materials plus labour plus overheads plus finishing plus contingency. Contingency is usually about 10% to cover waste, breakage and unforeseen work.
- Hierarchy of control
- The order for managing risk: eliminate, substitute, use engineering controls, apply administrative controls, then personal protective equipment as the last defence.
- Local exhaust ventilation
- Dust extraction connected to a machine to capture wood dust at source. It protects against respiratory harm and reduces fire and explosion risk in the workshop.
- Squaring procedure
- Plane a flat face side, square the face edge to it, then gauge thickness and width from those faces. All other marking and machining uses them as reference.