"Tim Wescott" wrote in message

I'm thinking that if the break has a stop that registers that "top"
edge
of the U the same for both sides, that we should be able to do
better
than 20 mil most of the time, and never exceed 50 mils unless
there's
just something wrong with the equipment.

When I became a draftsman the sheet metal foreman told me to assume a
tolerance of 1/32" (0.031") on bend locations, though they usually
could and did do better. I think the presence or absence of shearing
burrs on the edge made a substantial contribution. The Strippit that
punched the holes located on a small area near the corner rather than
the full width like the press brake's back gauge.

Does this sound reasonable to you, or am I all wet? Is this
something
that a normal sheet metal shop should be able to do, if they were
provided with suitably cut sheets?

Ask the ones you plan to send the quotes to. When I was designing
circuit boards I invited the sales reps to stop by to discuss their
normal and extra-cost tolerances in considerable detail. I suspect
they saw MITRE as a big defense contractor and didn't realize my
12-board prototype orders were all they would ever get.
jsw