Metal Stamping Basics — How It Works

Metal stamping is a cold-forming process where flat metal sheet or coil is fed through a press equipped with custom dies to cut, bend, and form parts. It is one of the most cost-effective methods for high-volume metal part production, capable of producing millions of parts with consistent quality.

The Stamping Process

1. Coil Feeding or Blank Loading

Material is fed from a coil through a straightener and feeder system, or pre-cut blanks are manually or robotically loaded into the press.

2. Die Operations

As the press cycles, the die performs one or more operations per stroke: blanking (cutting), piercing (hole punching), bending, drawing (cup forming), coining (embossing), and lancing (partial cutting).

3. Part Ejection

Finished parts are ejected from the die using air blow-off, mechanical knock-outs, or robot pick-up systems. Scrap material (skeleton) is typically wound for recycling.

Press Types

Press Type	Capacity	Speed	Best For
Mechanical Press	25–500 tons	100–500 SPM	High-volume, simple parts
Hydraulic Press	50–2000 tons	10–60 SPM	Deep draw, large parts
Servo Press	30–800 tons	Variable	Complex parts, precision
High-Speed Press	30–200 tons	400–1200 SPM	Connectors, electronics

Key Process Parameters

• Clearance — Die-to-punch gap, typically 5-15% of material thickness
• Stroke Length — Determines draw depth and available die space
• Press Speed (SPM) — Strokes per minute, affects cycle time and tool wear
• Blank Holder Force — Controls material flow in draw operations
• Lubrication — Reduces friction and extends die life