Replies

1. 
   Eef | Jan 21, 2010 04:37pm | #1

   hey,

   for me it kind of depends on the application. 1/3 the thickness of the stock is a good rule. it too can change. if the joint is used in a mechanical way, i would want the tenon deep and pinned. for fixed frames such as webframes one may not need much more depth than the 1/4 to 1/2" groove or plough that will house the panel. usually i go 1/2" here. did a whole kitchen once in which all the stiles and rails of the cabinet face frames were floating tenons in routed mortises. it worked fine. perhaps you could provide a bit more info as to what you plan/are doing?

   eef

2. 
   joinerswork | Jan 22, 2010 10:13am | #2

   Pilot,

   The 1/3 rule is not hard and fast. In the case of a 3/4" thick apron entering a 3" thick table leg, obviously, 1/3 of table leg thickness is impossible, and 1/3 thickness of the apron is impractical.

   So a little judgement on the builder's part is helpful, and depends a little bit too on his assortment of mortising chisels:)

   As far as the tenon's length is concerned, length determines mainly the glue area- and strength-- of the joint. As a rule, the greater the strain, the more glue area needed. So a stubby tenon might be sufficient for a lid on a small box, that will be lying in place, and gently lifted from time to time.. But a door for a large cabinet ought to have long tenons, to prevent its tendency to sag, and resist the forces of little tykes swinging on it, even to the point of extending thru the stile.

   As a general rule, though, many builders consider 3/4" x 5/16" a good tenon size, one shop I worked in typically used a 7/8 x 3/8" tenon. I like 1", wayyy strong; plus, making up a cut list, it is easy to calculate the overall length from the distance between tenons if you use 1" tenons;-) Adding fractions to fractions is HARD haha

   Ray