In stamping, everything we do with a press and die comes down to two fundamental mechanisms: plastic deformation and separation. Blanking and piercing are separation operations, and the single most critical parameter is die clearance. As a rule of thumb, we set clearance at 5% to 10% of sheet thickness. Go too tight, and you risk secondary shearing and elevated burrs; go too loose, and the collapse zone at the cut edge becomes pronounced. In practice, clearance selection also depends on material grade, thickness tolerance, and punch/die wear allowance—so it pays to build a small clearance window into the die design rather than locking in a single nominal value.
Bending and drawing belong to the deformation family, where springback and wrinkling are the usual troublemakers. For bending, we compensate springback based on the material's yield strength—typically reserving a correction angle in the punch geometry and validating it with a first-off trial. For drawing, the key checks are blank-holder force and drawing coefficient; insufficient hold-down force invites wrinkling at the flange, while excessive force causes thinning or fracture at the punch radius. Die materials and surface treatment also matter here: for high-strength steel or stainless, consider carbide inserts or PVD-coated tooling to control galling and extend die life.
None of these parameters live in isolation—clearance, springback compensation, and hold-down force all interact with press tonnage, ram speed, and lubrication. A die that runs well on one press can behave differently on another, so always validate with actual trial runs and document the settings. For more mold sourcing information and supplier resources, visit MoldSo at www.moldso.com.