Biscuit Joint Sizes (0, 10, 20) — Dimensions & Alternatives to Lamello

September 20, 2025

A wooden biscuit is an oval-shaped jointing element made of compressed beechwood, used for form-fitting joints in furniture making. The most common sizes are 0, 10, and 20. Regardless of size, the material thickness is always exactly 4 mm, making it compatible with the standard blade of a biscuit jointer.

What Exactly Are Wooden Biscuits?

Wooden biscuits, frequently referred to by joiners as plate biscuits or jointing wafers, serve to create invisible, high-strength connections between timber panels. They consist of cross-laminated, heavily compressed beechwood. When water-based wood glue is introduced into the routed groove, the beechwood reacts to the moisture. Much like a dry sponge expanding in water, the wafer swells slightly in thickness and locks securely into the slot. This process delivers exceptional tensile strength and torsional resistance within the timber joint.

Standard Sizes (0, 10, 20) and Their Dimensions

The dimensions of wooden biscuits are standardised across the industry. Because the biscuit thickness is exactly 4 mm across all three standard sizes, the cutter blade on the biscuit jointer does not need changing when switching sizes. The fitter simply adjusts the depth stop (plunge depth) on the machine.

Exact dimensions and required routing depth per component:

Size 0: 47 mm length × 15 mm width × 4 mm thickness. The required routing depth on the machine is 8 mm.
Size 10: 53 mm length × 19 mm width × 4 mm thickness. The required routing depth on the machine is 10 mm.
Size 20: 56 mm length × 23 mm width × 4 mm thickness. The required routing depth on the machine is 12.3 mm.

Usage & Selection: Which Size for Which Panel Thickness?

The choice of biscuit size is determined primarily by the material thickness of the workpieces being joined, whether using chipboard, MDF, or solid timber. The biscuit slot must not break through the surface of the board during routing.

Size 0: Used for narrow frames, trim strips, or thin panels with a material thickness of 8 mm to 12 mm.
Size 10: Suitable for panel thicknesses of 12 mm to 15 mm. Typical applications include drawer boxes or delicate, smaller cabinetry.
Size 20: The industry standard in professional cabinet making. This size is used for panels from 16 mm thickness upwards (typically with 18 mm or 19 mm cabinet components). It provides the maximum gluing surface and highest stability for wardrobes and heavy constructions.

Wooden Biscuits as an Alternative to Lamello

Over the years, the name Lamello has become a generic term for this type of timber joint. However, the name originated with the Swiss inventor and machine manufacturer of the same name.

Standardised wooden biscuits from alternative manufacturers are technically identical alternatives to the original brand. They feature the exact same dimensions, manufacturing tolerances, and swelling properties. For the installer, this ensures 100-percent compatibility with existing biscuit jointers. The cut pattern, precise fit within the groove, and strength of the final assembly remain identical.