A flat piece of compressed beech wood inserted into matching semi-circular slots cut by a specialized joiner. When water-based wood glue is applied, the wafer swells inside the slot, locking the two pieces together. They provide excellent vertical alignment for panel glue-ups but offer minimal structural strength compared to traditional tenons.
Heard on the job
Plunge a biscuit slot every eight inches along the edge so these boards stay perfectly flush during the glue-up.
Do not mix it up with
- Dowel: Biscuits are flat ovals that align wide panels laterally, while dowels are round pegs that provide much higher shear strength.