Ask WWGOA: Joiner Biscuit Sizes


Question:

I ordered a Porter Cable biscuit jointer and was wondering what size biscuits to order. How do you determine what size biscuit is used for a particular job. I have read about PC’s FF size but am still confused. Your advice is appreciated.

Submitted by HHolmes

Answer:

The three common biscuit sizes are 0, 10, and 20. You can find these almost anywhere, from home centers to specialty stores. While biscuits are a great joinery solution, they do have a few limitations. One is the length of the slot required to use a biscuit. Even the smallest biscuit, the 0, requires a slot that’s too long to use on the end grain of a 1-1/2″ wide face frame rail. This problem is solved by the FF biscuits. They’re round, instead of football shaped, and require a different cutter. Biscuit joiners typically use a 5″ diameter cutting blade. Some machines, like the Porter Cable 557, allow you to swap to a smaller diameter blade and use the FF biscuits. If your machine doesn’t allow the change to a smaller blade, you can’t use the FF biscuits.

When choosing what biscuit to use, go with the largest biscuit that will work for your application.

George


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One Response to “Ask WWGOA: Joiner Biscuit Sizes”
  1. Jeff

    A standard biscuit blade is not 5″; it is 4″ x 5/32″ which is an approximation of the metric size 100 mm x 4 mm. The arbor is 22 mm or 7/8″.

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