Biscuits (Compatible with Lamello): Sizes 0, 10, 20 and Dimensions Explained
A wooden biscuit, frequently referred to after the original manufacturer Lamello, is an oval jointing plate made from compressed beech wood. It serves to create non-positive, dimensionally stable connections between wooden components. With the application of wood glue, the material swells within the routed slot, anchoring itself permanently into the workpiece.
What Are Wooden Biscuits Exactly?
Wooden biscuits are used in cabinet making and joinery to join panel materials such as chipboard, MDF, or solid timber with great precision. Installation requires a dedicated biscuit jointer (groove cutter), which cuts an exact, crescent-shaped slot with a standard width of 4 mm into the edges of the wood.
The cut slot is deliberately made slightly longer along its longitudinal axis than the plate itself. This gives the installer lateral leeway during gluing to align the components perfectly flush before the glue sets. As soon as water-based wood glue meets the dry, compressed beech wood, the biscuit expands by fractions of a millimetre and wedges itself into the groove like an anchor.
Common Sizes: 0, 10, and 20 in Detail
The industry has standardised three main sizes, designed for various material thicknesses. The routing width (thickness) remains constant at 4 mm across all three variants.
- Size 0: Dimensions 47 mm x 15 mm x 4 mm. Routing depth on the machine: 8 mm. Suitable for narrow components and material thicknesses from 8 mm - 12 mm.
- Size 10: Dimensions 53 mm x 19 mm x 4 mm. Routing depth on the machine: 10 mm. The standard for medium material thicknesses from 12 mm - 15 mm.
- Size 20: Dimensions 56 mm x 23 mm x 4 mm. Routing depth on the machine: 12 mm. The most frequently used size for common furniture construction panels with a thickness from 16 mm upwards (e.g. 19 mm thick carcass panels).
Dimensions and Technical Standards
The geometry of the wooden plates is standardised to guarantee compatibility with all standard biscuit jointers on the market. The 4 mm thickness is dictated by the standard blade width of the jointer. The wood grain runs diagonally to the lengthwise orientation of the biscuit, which massively increases the joint's breaking resistance.
During construction, the correct routing depth must be set precisely on the machine. For a Size 20 biscuit (23 mm total width), a 12 mm deep slot is routed into each of the two workpieces being joined. The sum of the routing depths (24 mm) is intentionally 1 mm deeper than the biscuit is wide. This remaining cavity acts as a reservoir for excess glue.
Usage and Selecting the Right Size
Choosing the right wooden biscuits depends primarily on the thickness of the base material. For classic cabinet making using 19 mm thick decorative panels, the choice almost always falls on Size 20. For mitre joints or very thin drawer sides, Size 10 or Size 0 are used.
An essential installation principle is: select as large a biscuit as possible without the routing cutter breaking through the material's surface. For particularly wide components, multiple biscuits are spaced 100 mm - 150 mm apart to distribute the load evenly.
Related Terms
- Wooden dowels: Cylindrical jointing pins (fluted dowels) that are glued into drilled holes (often using System 32) and offer no lateral tolerance.
- Cam and dowel fittings: Mechanical, demountable carcass connectors made of metal that require no glue.
- Tongue and groove joints: A traditional wood jointing method for which biscuit jointing technology serves as the modern, machine-assisted equivalent.
Matching Category
All standardised sizes for professional furniture making can be found in our range of wooden biscuits.