On Thu, 3 Mar 2005 15:52:16 -0500, "Mike Marlow"
wrote:


"J" wrote in message
...

And is much wider. The cross section of the typical biscuit is much larger
than the cross section of the dowel.
A #20 biscuit has a cross sectional area of 0.35 sq in. You would need a
dowel 2/3 inches in diameter to match that cross section.
Not easy to use that size of dowel in 4/4 stock. :-) This is why the
loose
tenon was invented.


What about the cross section of two dowels in the same space a biscuit would
occupy?


shear is a direct function of section. a dowel with a given section is
much thicker than a biscuit of the same section, so it weakens the
board it's in more. dowel joints often fail by blowing out the wood
surrounding the dowel rather than breaking the dowel itself.