Probably sheet steel for full length pieces. Maybe up to 1/4" or thereabouts at max for smaller sections of metal.
Here is a quick down and dirty V strike For 1/4” material. You will have to watch your hydraulic pressure as the top coining radius will set the metal less than 90°. This will change with wider metal and thicker metal or slightly thinner. The top coining radius is usually about 10% smaller than the medium radius which is about the centre of the steel. If you don't have enough tonnage to set the proper coin you can sharpen the top punch two less than 0.056 radius. But, the sharper the coin the weaker the bend will be.
It does not need to be cut to 80°. But it does need to be cut to less than 90°. The coining radius will sweep it to a 90° corner as long as the top punch has been relieved enough below 90° to prevent spring back. You could even cut it to 70 or 75°. But this makes a sharper blade. you want to keep your nose radius on your top punch to no less than 0.056 inches and less you run out of tonnage.
Hot rolled will work just fine for maybe 10-100 hits. It is the top punch that will take the punishment when your tonnage is running out. The top punch and bottom die if they're wider than 10 inches you'll run out of tonnage. Something like this I would run in 100 ton press, With lubrication for both top and bottom punches with top punch hardened for 100 hits, quarter inch thick an 1 foot wide.
These are the specs that swag offroad quoted on their bending break for the harbor freight 20 ton press. 19" = Full bending width of the bottom die on anything 3/16" or thinner. 15" in 1/4" 13" in 5/16" 11" in 3/8" 6" in 1/2" 3" in 5/8" Any idea where I can get a hardox or chromoly piece of steel approx 1 inch by 1inch from? I would like to weld it onto the tip of the 1" mild steel plate I have to increase the wear resistance and durability.
I stopped by a metal fab shop they make their own bending brake blades. The owner said they just use mild steel and it lasts a long time. Can be resharpened as needed. So I'll just stick with the steel plate I have. I may try using a tool steel tig rod to weld on a surface coating of tool steel at a later point to toughen it up if it seems to be taking a beating. Half inch does seem a bit optimistic.
Made more progress on the bender. Drilling holes through so much metal was very time consuming. The 2 poles that the system slides up on are a hair too snug, so I'll see if I can sand them down a smidge to ensure a better fit. Tomorrow I'll work on the blade. The metal shop owner said any angle between 60 and 90 degrees for the edge should be fine. Also got a 1.25" thick steel plate plasma cut out for me to act as a sturdy base for it all to rest on. I need to make or buy springs to push it apart.
Ha. Indeed. I added blade spacers and threaded and tapped some set screws in to hold the blade in place. I'm working on cutting out the blade now. The angle on the edge is going to be difficult but I'll try my best. Also I'm officially a man now, I broke my first tap...
Holy jumping. I can give you three different ways to remove a broken tap easy. Two out of the three would be using milling machine. The other one would be sink or wire EDM.
