Stamping is fundamentally simple: a press and a mold apply force to sheet, strip, tube, or profile stock so the material either plastically deforms or separates into the required shape and size. Every operation we run in the shop—blanking, piercing, bending, drawing, flanging—is just an expansion of that one sentence. Take blanking as the baseline case. Die clearance is typically set at 5% to 10% of sheet thickness. Go too tight and you get a secondary shear band on the cut face; go too loose and you invite burrs and edge collapse. No chart replaces trial runs here—you sneak up on the right feel one shim at a time, watching the fracture zone on each trial part.
From there, the tooling logic branches. Piercing follows the same clearance rules as blanking but demands tighter punch-to-die alignment to avoid slug pulling and punch chipping. Bending shifts the concern to springback and bend radius—die radius should generally stay at or above sheet thickness to prevent cracking on the outside fiber, and compensation for springback usually means overbending a degree or two and dialing it in on the press. Drawing is where mold design earns its keep: draw radius, blank-holder force, and lubrication all have to be balanced against wrinkling on the flange and tearing at the punch corner. Flanging then adds edge stretching, so pre-pierced hole edges need enough margin or they split.
The common thread across all five operations is that clearance, radius, and force are never independent—change one and the others move with it. That is why a mold that runs clean on 1.2 mm cold-rolled steel can fail immediately on a different coil lot. Good process sheets record the trial-and-error history, not just the final numbers. For mold sourcing, supplier comparisons, and more tooling know-how, visit MoldSo at www.moldso.com.