Forging, rolling, extrusion, wire drawing, deep drawing methods compared
Open-die: simple shapes. Closed-die: complex, high volume. Forging temp: 1100-1250°C steel. 15-25% stronger than machined.
Hot: above recrystallization. Cold: Ra 0.4-1.6 µm. Reduction: 10-30% hot, 5-15% cold per pass.
Direct: ram pushes. Indirect: 25-30% less friction. Ratio up to 40:1 for Al.
Draw ratio max 1.8-2.0 for steel. Ironing reduces wall thickness.