Stamping is a cold-forming process where a press applies external force to sheet, strip, or tube material, causing plastic deformation or separation to achieve the required shape and dimensions. On the shopfloor, a typical stamping die set consists of upper and lower die shoes, punch and die inserts, guide pillars and bushings, a stripper plate, and locating pins. These are matched with either a crank press or a hydraulic press. Common materials include SPCC cold-rolled steel and SECC galvanized steel, with thicknesses usually ranging from 0.2 mm to 6 mm. A single press stroke can complete blanking, piercing, bending, or drawing. From a die maintenance perspective, guide pillar clearance and stripper spring force are the two factors that most often cause inconsistent part quality when they drift out of spec.

Take a simple motor end cover as an example. It typically goes through four operations: blanking, drawing, sizing, and piercing. The clearance control at each stage directly affects burr height and dimensional accuracy. In blanking, clearance is usually set between 5% and 8% of material thickness per side; too large and burrs grow, too small and die wear accelerates. For drawing, the die radius and blank holder force must be balanced to avoid wrinkling or tearing. In our shop, we check punch-to-die clearance every 5,000 strokes on high-volume runs, and we track burr height with a simple profile gauge. If burr exceeds 0.05 mm on SPCC, we know it is time to resharp or adjust the die.

Die material selection also matters. For long-run stamping, SKD11 or Cr12MoV inserts with HRC 58–62 heat treatment give stable edge life. For softer materials like SECC, a TiCN coating can reduce galling and extend tool life by 30–50%. The key is to match die design and press tonnage to the actual material and batch size, not just the part drawing. For more mold sourcing and technical resources, visit MoldWorld at www.moldw.com.