This is easily doable on your 20 ton press. Buy the book, "Fundamentals of Press Brake Tooling" from Amazon for about $60, and it should give you all the info you need.
Bending the U in a single press won't be easy as it's difficult to counteract spring back. It'll be much easier to do this with a regular 90 degree die in two presses (which will of course be less than 90 degrees). The book should tell you how much exactly. You'll need a gooseneck die of course, and it'll be offset from center a bit. Not difficult by any means though.
As for materials, on a short run with light weight materials, you can probably get by with plain old A36 hot rolled. 4140 prehard would be better though. Tool steel, probably overboard. |