Straightening A C-clamp?

brino

brino

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Hi All<

I picked up half a dozen 4" and a half dozen 6" new old-stock Eclipse c-clamps from my local tool guy.
Eleven were perfect.....one of the 6" ones is twisted:

side.jpg
clamp1.jpg
clamp2.jpg

Is it possible to straighten this clamp?
I was just going to heat the "spine" with oxyacetylene and try to un-twist it.
Any one have experience; is this a reasonable approach?
Should I pre-heat? Do I need to cool slowly?
Obviously the nice blue paint won't survive.....

Thanks,
-brino
 
heat, twist, and pray. Worst that will happen is that you end up breaking it and it gets re-purposed as a bench dog.

If it goes back into shape, it should be just fine. Cast iron is ductile :)
 
Hu, Cast Iron is ductile????

Not in my book, it isn't.

Most of the cheaper variations of C-clamps are ductile iron, which has ductility in the material.

The really good one's are forged from a grade of steel like 4140 or 6150 and are stress relieved and heat treated.

Heat it up with a rose bud to near cherry red and carefully bend back in shape and air cool. Don't quench with a water hose!
 
Cant you get an exchange? It's not like the goods are second hand.
 
brino,

It looks like the hole was tapped crooked in the first place. +1 on what Riaan said. Talk to your tool guy about the problem; ask him for a replacement or refund. If you have no luck there, then try to straighten it.

Bob
 
It's weird, I bought a handful of these exact same Eclipse clamps just this saturday, I'm going to have to inspect them now!

That's pretty schocking quality control there.
 
I have straightened C-clamps by clamping them in a vise and bending them with a large crescent wrench or appropriately sized hammer with no heat. I've never broken one.

I figure that if the metal they are made of won't bend, then they wouldn't be bent.

It does kinda look like the threaded hole is drilled crooked. I've seen that on a motorcycle mirror thread adapter before.
 
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Clamp in bench vice, put adjustable wrench on beam, bend till straight.
If it breaks throw in scrap bin. If it didn't break when bent the first time why would it the second time?
 
And on the other hand, if it bends too easily, it's not much of a clamp and will likely twist during use. It's possible the heat treat isn't right or wasn't done on that one.
 
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