Barrel & Action Wrenches???

[nanuk]

do you think that using saw cuts and make a few kerfs could accomplish the same thing?

[JIMinPHX]

I don't know what a kerf is. I would expect that taking off a few thousandths with a file would be all that is really needed.

You could probably also get this to work by taking a couple of pieces of 1/8" x 1/4" metal stock or even thin pieces of shim stock & stacking them on the outer edges of the blocks.

This center relief idea worked well on my blocks that had a rather thin cross section at the top. My thin aluminum blocks can probably bend a little under heavy pressure. On a thicker block, this idea may not work at all.

[MBTcustom]

Anything that get the pressure to the sides of the blocks and not on the middle will do the trick. You could also use a pusher block that has relief cut down the middle so as to provide pressure to the sides of the block.
This is a simple concept. if you are only exerting pressure along the flat top and bottom of the blocks, then when they start to deform, the sides will pull away from the barrel first, leaving you with about the same effect as vicing between two parallel surfaces. But if you exert pressure on the sides of the blocks, then you get a collet action that never loses full contact.
Excellent idea! I wish I had thought to use it on my setup.

[nanuk]

Jim, and GS have explained it well.

I understand now.

Jim, a kerf is the slot removed after a blade has made a cut. at least that is what I call 'em