On Tuesday, May 7, 2013 1:45:41 PM UTC-7, Tom Gardner wrote:
I need to clamp a 3/4" square x 1/4" thick insert into a tool.
I'm picturing a carbide cutter with a rabbit's-tooth function...
Consider clamping it against a soft gasket (copper or aluminum)
so that the soft material will deform into tool marks in the
seat and the insert, to hold it from shifting.

So, you'd make the clearance near zero, and use a five mil gasket.
Or, make the clearance -.005, and lock the insert into position
by adhering a pinch of carborundum grit onto the metal face it clamps against.