Stamping is still the backbone of high-volume sheet metal production, and from a tooling standpoint it is straightforward: a press applies force through a matched die set to plastically deform or shear the workpiece. In practice we split the process into two families. Separation operations—blanking, shearing, piercing, trimming—cut the sheet along a controlled contour, with punch-to-die clearance typically set at 5–8% of material thickness per side for cold-rolled steel to keep burr height and edge quality in check. Forming operations—bending, drawing, flanging, bulging—reshape the material without intentional fracture. The die design decisions differ sharply between the two: a blanking die lives or dies by clearance and stripper force, while a drawing die is governed by draw radius, blank-holder pressure, and lubrication.
A typical automotive door inner panel shows how these operations stack up. A 1.2mm cold-rolled steel blank goes through drawing, trimming, piercing, and flanging, and the full tooling set often runs to a dozen or more progressive or transfer dies. Dimensional tolerance on the finished part is usually held within ±0.1mm, and where surface quality matters—outer panels, visible Class A surfaces—an extra restriking or sizing station is added rather than trying to hit final geometry in the draw. In the tool room this means planning die sequence and datum strategy up front; retrofitting a restrike station into an existing line is far more expensive than designing it in. Springback compensation on the draw and flange stations deserves the same early attention, especially on higher-strength grades.
What separates a stable stamping line from a troublesome one is usually not the press tonnage but the details: consistent blank-holder pressure, proper die entry radii, and a maintenance schedule that tracks wear on cutting edges before burr height drifts out of spec. Keep those under control and the ±0.1mm window stays comfortable across long production runs. For more mold and die sourcing information, visit MoldSo at www.moldso.com.