flattening curved sheet steel

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?


Reply to
Tove Momerathsson
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Hydraulic press?


Reply to
Grant Erwin

Reply to
Randy Zimmerman

Bad news - best just ship them here.

Martin :-) "I'm experimenting using a RR rail - across the center of the bow - and the end - pulled up by another plank of steel. I'm hoping to re-curve it back straight. Maybe I'll get an S curve - time will tell.


Reply to
Martin H. Eastburn

"Tove Momerathsson" wrote: (clip) Any suggestions how to flatten them out? ^^^^^^^^^^^^^^ I wouldn't do anything right away. Chances are you will cut pieces off of these strips, and use them up in various ways. Just do what you have to do, with a hammer and anvil, to handle each job as it comes up. It may be hard to get the full strips dead flat, but shorter lengths will probably be easy. As you get more familiar with the way they act, the full strips will get easier also.

Maybe you can design a project that NEEDS a bunch of curved strips. :-)

Reply to
Leo Lichtman

If these were curved when they were sheared they also have some twist in them. Place one end in a big vise and untwist them with a big Crescent wrench. There is a lot of residual stress in these and they straighten quite easily. As the twist comes out so does most of the curve. We correct hundreds, if not thousands of pieces a year with this tecchnique. Leigh at MarMachine

Reply to

Place the pieces in a stack with the bow up, and support the ends on 2 blocks of about 4" high or more. Place a weight of widely distributed mass to create an inverse of the bow. The weight object shouldn't create a small area/footprint of pressure.

The weight could be a bag of sand, cement, an unbound bundle of shingles or other non-rigid mass. You may need to add some additional weight on top of it, but a wide, soft weight should remove the bow, maybe in as few as a couple of days.

WB .................

Reply to
Wild Bill

I agree with the advice to not bother with them 'till you use them. Nice find though, can't beat the deal.

I built a 27' dump trailer box (with darn little help, as it turned out) out of square tube and sheet from oil tanks, sides and bottom each one piece. There was some serious pulling on that one to get the sheet dwawn down..


Reply to

While this would work with certain materials, some plastics for instance, it's not going to have any effect on steel at room temperature unless the load is great enough to exceed the steel's yield strength. In which case the effect will be immediate, but will be difficult to control. Much better to control for deflection than applied load.

Ned Simmons

Reply to
Ned Simmons

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