Need to produce a very small-radius bend while keeping the outside surface of the bend free of cracking and deformation? V-grooving could be for you. Tolerances in bending involve more than just the angle tolerances shown on the print. Materials also have tolerances, both in thickness and yield strength. If you’re bending cold-rolled steel and other anisotropic material, inconsistent grain direction can lead to inconsistencies at the press brake. Why is a press brake called a press brake? In short, the verb “brake,” as used in sheet metal shops, comes from a Middle English verb that meant “to bend.” Press brake guru Steve Benson describes five types of radii that can be formed in air bending, from sharp bends up to profound radius bends. Old press brakes with planer tooling still can produce good parts. You just need to maintain them properly, realize their limitations, and account for the inconsistencies of planer tooling. Columnist Steve Benson helps a reader dial in the 20 percent rule to better predict the inside radius when air forming. Bending guru Steve Benson continues his deep dive into the k-factor, arguably the most important variable in precision sheet metal fabrica...