What's new
What's new

Large Radius Bend in 3/8" Plate

Econdron

Hot Rolled
Joined
May 31, 2013
Location
Illinois
Looking to do a small run on just (4) bends in 3/8" plate, with like a 2" or 3" radius bend (flexible on the exact radius). Bends would be in mild steel on a 28" long plate. I have a 50T shop press and a 25T x 6' press brake. I've made tooling before to do a similar bend on 3/16" thick material and it worked out great. I basically just cut a bunch of die sections from 3/8" plate and welded them together to create a half-pipe shaped die and used a solid round piece for the punch. I did that in the shop press as the parts were only 10" wide. Can anyone think of a way to do this bend with? I could probably do it from (2) 3/16" thick pieces and weld them together at the seams. Other option would be to cut a pipe and weld 3/8" plate, but that's a lot of welding and grinding and I'm worried it would look skewed.
 
Do you have a hydraulic or mechanical brake?

If you have a hydraulic, you can just weld a tang to a piece of solid round and bend that into a wide bottom die. Since it is only 30" long, you can build the bottom die out of heavy duty angle and install a guild plate for centering. I personally like to machine a 1/2" deep x 1/2" wide groove into the solid round for stability. Then weld it on. No set screws.

If you have a mechanical, that is different as you don't have the great tap, tap, taparoo that you have with a hydraulic. You can get seriously hurt if you don't set the machine right with odd made tooling. You can have proper dies made at some good expense for such a small run.

Note: when I build custom dies, I tend to overbuild the hell out of them. This allows for safety along with long term use. I also have machined dies from alum blocks for a couple bends, but that was for stuff like 10" long.
 
does it really need to be 1 bend or can you bump bend it" especially for low volume it can be a easy solution.
Agreed! Divide it up into 6 or 8 bends and it will come out smooth and no need for stuffing around making custom dies.

Also 50t sounds a bit lite to be pressing this in one pass anyway?
 
I also think you need quite a bit more tonnage. I checked a press brake calculator for your specs using a 3" v die for a 90deg bend and got 77 tons recommending a 100 ton machine.
 
Do you have a hydraulic or mechanical brake?

If you have a hydraulic, you can just weld a tang to a piece of solid round and bend that into a wide bottom die. Since it is only 30" long, you can build the bottom die out of heavy duty angle and install a guild plate for centering. I personally like to machine a 1/2" deep x 1/2" wide groove into the solid round for stability. Then weld it on. No set screws.

If you have a mechanical, that is different as you don't have the great tap, tap, taparoo that you have with a hydraulic. You can get seriously hurt if you don't set the machine right with odd made tooling. You can have proper dies made at some good expense for such a small run.

Note: when I build custom dies, I tend to overbuild the hell out of them. This allows for safety along with long term use. I also have machined dies from alum blocks for a couple bends, but that was for stuff like 10" long.
It is hydraulic.
does it really need to be 1 bend or can you bump bend it" especially for low volume it can be a easy solution.
That's so simple! I can't believe I never thought to try that. I'll see what the biggest die I have is and play around with some 3/8" plate and see what happens.
 








 
Back
Top