On Jan 20, 9:07*pm, Ned Simmons wrote:
On Sat, 19 Jan 2008 22:24:39 -0800 (PST), John Martin
I don't have a Lufkin catalog handy, but I'm guessing that what you
have may be shaper hold downs. *Used also with milling or grinding
machines, to hold down thin parts.

Nice catch, John. Now tell us how the heck they work.

--
Ned Simmons

Ned, I've got a couple of pairs of those sitting in my toolbox, but I
can't tell you how they work - because I don't recall ever using
them. I know how they are SUPPOSED to work, though.

Flat side down, bevel up. Thin side against the side of the
workpiece, thick side against the vise jaws. Since the thick side is
ground at less than 90 degrees it will bear against the vise jaws only
at its top edge, which will apply downward force as well as the
horizontal force from the vise jaws to the workpiece.

That's the theory. I wouldn't hesitate to use them on the surface
grinder. Shaping or milling generates a lot more force however, and
I'd be reluctant to use them for anything more than light cuts on
those machines. They are called shaper holddowns, though.

John