Marking gauge
A woodworking tool consisting of a beam with a marking pin or knife that scribes lines parallel to a reference edge at a set distance.
Read the definitionThe glossary
The trade terms you'll come across.
Plain-English definitions for the words that turn up when you're buying, specifying or working with timber.
MDF
Medium density fibreboard — an engineered panel made from wood fibres bonded with resin under heat and pressure. Uniform density and smooth surface, widely used for painted cabinetry.
Read the definitionMedullary rays
Bands of cells that run radially from the centre of the tree toward the bark, used by the living tree for storage and transport across the trunk.
Read the definitionMicroclimate
A microclimate is a local zone where temperature and humidity differ from the surrounding space (e.g., near radiators, exterior walls, inside cabinets). In woodwork, microclimates can cause uneven moisture exchange and lead to cupping or distortion.
Read the definitionMicrofibril angle (MFA)
Microfibril angle (MFA) is the angle between cellulose microfibrils in the S2 layer of the cell wall and the cell’s long axis. Lower MFA generally increases stiffness and keeps longitudinal shrinkage low; higher MFA (common in juvenile and reaction wood) increases longitudinal shrinkage and distortion risk.
Read the definitionMineral streak
Dark discoloured bands running along the grain, formed by chemical deposits (often iron) accumulated in the tree. Common in walnut and oak.
Read the definitionMixed lengths
Lumber sold with a range of board lengths in a bundle rather than sorted to a single length. Common for lower-grade hardwood lumber.
Read the definitionModulus of elasticity
A measure of wood stiffness — the ratio of stress to strain under bending load. Indicates how much a board will deflect under load. Also called MOE.
Read the definitionMoisture content
The amount of water in wood expressed as a percentage of the oven-dry wood mass.
Read the definitionMoisture gradient
The difference in moisture content between the outer layer (shell) and inner core of a piece of timber during drying. A steep gradient causes drying stresses that lead to checking, honeycombing, and case hardening.
Read the definitionMoisture gradient
A moisture gradient is a difference in moisture content between the surface and the core (or between faces) of a piece of wood. Gradients create internal stress during drying and can cause distortion when material is removed or conditions change quickly.
Read the definitionMortise and tenon
A woodworking joint where a protruding tenon on one piece fits into a matching mortise (slot) on another. One of the strongest and oldest wood joints, used in framing and furniture.
Read the definitionMovement factor
The degree to which wood expands and contracts with changes in moisture content. Tangential shrinkage is typically 1.5-2x radial shrinkage, causing significant movement in flat-sawn boards.
Read the definitionMultiseriate rays
Wood rays more than one cell wide, visible as broader horizontal bands in cross-section. Characteristic of most hardwoods.
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