| Term |
Definition |
| Imperfection | Defect or irregularity that affects the appearance of a piece but does not make it unsuitable for its intended purpose. |
| Interlocked grain | Grain structure where the angle of the fibres changes or reverses in successive layers. |
| Joint group | Structural classification that rates different timber species in terms of their joint strength and properties. |
| Kick-out | Decrease in thickness at one end of a piece due to it lifting slightly as it leaves the roller in a moulder or planing machine. |
| Kino | Gum-like substance, often black to red in colour and rich in tannins, found especially in eucalypts. |
| Kiln | Enclosure used for drying timber under controlled conditions, where temperature, humidity and air circulation can be adjusted. |
| Kiln dried (K/D) | Timber that has been dried in a kiln to a particular moisture content (generally 10-15% unless otherwise specified). |
| Knot | Branch that has been surrounded by wood tissue in the stem and appears in cross section in the re-sawn timber. |
| Knot area ratio (KAR) | Ratio of the area of a knot compared to the area of the end section of the piece – used in softwood visual stress grading to assess the relative size of knots. |
| Knot cluster | Two or more knots grouped closely together so that the grain is deflected around the entire cluster. |
| Knot group | Two or more knots grouped together, but far enough apart to allow the grain to pass between them. |
| Laminated veneered lumber (LVL) | Engineered product made from timber veneers glued together, with the grain of all veneers running lengthwise along the beam (unlike plywood, where the grain in every second layer runs at right angles). |
| Latewood | Higher density band of wood in a growth ring. Also called ‘summerwood’ since it generally occurs in summer, towards the end of the growing season. |