bending 4130 .125 X 1"

[PoconoJohn]

What is the best way to bend 4130 sheet 1/8" thick X 1" wide? It needs four bends in a piece about 9" long. Thanks!

John C

[Dana]

Heat it. It's super easy to bend when red hot. Clamp one side in a vise with a suitable radius form to bend it around, heat the bend zone with a torch, and tap it around with a hammer. Then heat it again and let it cool slowly to stress relieve.

[PoconoJohn]

Thanks. I tried that but the vise sucks all the heat. I tried with a MAP torch set (I don't have a welding set-up). I've used heat on other parts, but 1/8" inch is too thick. I was thinking of a metal bender from Harbor freight, but I'm not sure if it will work. The description says it can bend 5/16 in. x 1-1/4 in. or 1/4 in. x 2 in. mild steel...but not sure about 4130. I might end up taking it to a fabrication shop.

[Dana]

If the bender can bend 1/4" mild steel it can certainly bend 1/8" 4130... but you'll still want to stress relieve it afterward.

You can also clamp the form in the vise and hold the workpiece in vise grips and heat it that way and then hammer it around the form, but it won't be as accurate, dunno if that matters. You can also clamp it in the vise a bit higher, so the bend area and form are farther away from the heat sucking jaws. But it is hard to get enough heat with a small torch.

I have a couple of pieces of cut off rounded edge from some aluminum angle, the rounded edge makes a good bending form.

[WLIU]

Place two sacrificial blocks of hardwood into the vise to hold the part to be bent. The wood will provide thermal isolation from the vise as you apply heat. You can also put the desired bend radius on the edge of the wood block that you are bending the part around. You might want a squirt bottle of water nearby just in case the wood does more than char.

Best of luck,

Wes

[PoconoJohn]

Thank you!