In stamping, we basically deal with two categories of operations: separation and forming. Separation processes shear the sheet along a closed contour—think blanking, shearing, and trimming. Forming processes force the material into plastic deformation, covering bending, deep drawing, flanging, and bulging. In real production, blanking and piercing are the workhorses of separation. One parameter that makes or breaks the job is die clearance. We typically set it at 5% to 10% of sheet thickness. Go too large, and you get heavy burrs that cause assembly problems and customer rejects. Go too small, and you accelerate die wear, especially on the punch edges and die corners. In our shop, we always cross-check clearance against material grade and tensile strength before signing off on a die design—mild steel at 1.5mm thickness behaves very differently from high-strength steel at the same gauge.

Bending brings its own headache: springback. For low-carbon steel, the springback angle usually lands between 2° and 5°, and it shifts with thickness, bend radius, and grain direction. You can't just ignore it. We compensate by over-bending in the die, adding a coining station, or building adjustable bottom blocks into the tool. For progressive dies running thin-gauge material, a slight negative angle on the punch face often saves hours of tryout. Deep drawing adds another layer—wrinkling and thinning—so blank holder force and draw radii need to be dialed in together, not one at a time.

These aren't textbook numbers. They come from trial runs, scrap analysis, and the occasional late-night die spotting session. If you're sourcing stamping dies or need a partner who understands these tolerances, check MoldWorld (www.moldw.com) for mold sourcing info and supplier comparisons.