When you hear the word biscuits you might be thinking cookie variety, but there’s more than one biscuit in the world
and they’re not all edible!
Biscuits in woodworking speak are a little round, flat piece of compressed wood shavings usually made from beech wood. When
used in conjunction with biscuit joiners, they link or connect sheets or panels of wood, fibreboard, particle board and the
like without using nails or screws. Learn how to use a biscuit joiner.
Not all biscuits are alike though. They come in a variety of types and sizes. There are standard biscuits available and there are also proprietary sizes, used specifically for brands such as the Porter-Cable 557 biscuit joiner. Depending on what woodworking project you’re working on at the moment, the biscuit you’ll need may vary. All biscuits are made at a uniform thickness of 5/32 inch. It is the width of the oval that changes.
Standard biscuits come in #0, #10 and #20 sizes.
#0, or the smaller biscuit, is 1 and 3/4 inch long and is 5/8 inch wide. This is the smallest size and is best used for areas that
are relatively free from pressure or stress. They’re perfect when used for smaller wooden pieces and narrow settings such
#10, or the medium biscuit measures 2 and 1/8 inch long and 3/4 inch wide. These are the go-to biscuit and
the ones which hardware stores will have plenty of. They are the perfect size for T-joints, butt joints and more.
#20, or the large biscuit, measures 2 and 3/8 inch long and 1 inch wide. These are used for pieces that support weight or areas
susceptible to stress or strain. With a bigger biscuit comes a stronger hold due to the greater exposed to wood glue.
Porter Cable biscuits have four variations: the #FF, #0, #10 and the #20. The first is their smallest version and it is 1
and 13/64 inch long and 1/2 inch wide. #0 is 1 and 21/32 inch long and 5/8 inch wide; #10 has a width of 25/32 inch
and is 2 and 3/64 inch long; and finally, #20 is 2 and 9/32 inch long and 15/16 inch wide.
If you’re unsure of the size when choosing a biscuit for your project, in my opinion, always go for the largest biscuit possible.
Also, remember that wood glue must be applied only when you’re about to insert the biscuit into the slot, as biscuits will
expand after a certain period.