You might try peening the short curved edge. I would try a hammer blow
every four inches along the three foot length. You will need an anvil or
something solid.
Are both edges sheared or only one edge? If one edge is flame cut and the
other is sheared that might be the problem.
Randy
"Tove Momerathsson" wrote in message
...
I made a small curbside find today, a 3" stack of sheet steel pieces
with a "FREE" sign taped to them. So into the truck they went. The
pieces are 6-10" wide by 30-36" long and range in thickness from 1/16"
to 1/4". Unfortunately, most of the thicker stuff is a bit curved,
bowed the long way anything from 1/2" to 1" at the center. I'd guess
from stress caused by shearing them to size.

Any suggestions how to flatten them out?

Tove