Roy Smith wrote:
I've got a Unisaw that I want to attach an extension table to the rear of.
There's two holes (approx 3/8" diameter) already drilled in the rear flange
of the cast iron top (it came from the factory that way), but they're not
tapped; just through-drilled. They're a little too small for clearance of
a 3/8" bolt;

Why not just use a 1/4" or 5/16" bolt with a nut on the back side?

Chris