The narrower the die opening, the more tonnage it will take to bend a part. So when air forming, how do you select your bottom die opening? Do you choose a die opening that’s 6 times the material thickness, 8 times, 10 times, or even 12 times? But over the past several decades, air forming has become the industry standard. Figures are courtesy of ASMA LLC, 2952 Doaks Ferry Road N.W., Salem, OR 97304, 50, smartphone Bottoming and coining with the press brake had its heyday. Material alsoĬomes from FMA’s Precision Press Brake Certificate Program, presented by Benson and held at locations across the country. The information comes from the Fundamentals of Press Brake Operations e-Fab online training program, presented by Steve Benson of ASMA LLC and available from the Fabricators & Manufacturers Association. Figure 1: In the bend allowance calculation, you use the complementary bend angle.Įditor’s Note: This is the first article in a series on press brake operation basics.