Page 184 - Mechanical Engineer's Data Handbook

Manufacturing technology
~

5.1 Metal processes

Metals can be processed in a variety of ways. These can processes for metals, although some may also apply to
be classified roughly into casting, forming and machin- non-metallic materials such as plastics and compos-
ing. ites.
The following table gives characteristics of different

General characteristics of metal processes

Minimum
Economic Materials Optimum section Holes Inserts
Process quantity (typical) size (mm) possible possible

Sand casting Smallbarge No limit 1400 kg 3 Yes Yes
Die casting, Large AI, Cu, Mg, 1-50 kg 3 Yes Yes
gravity Zn alloys
Die casting, Large AI, Cu, Mg, 50g to 5 kg 1 Yes Yes
pressure Zn alloys
Centrifugal Large No limit 30mm to lm 3 Yes Yes
casting diameter
Investment Smallbarge No limit 50g to 5Okg 1 Yes No
casting
Closed die Large No limit 3000 cm3 3 Yes No
forging
Hot extrusion Large No limit 500mm 1 - No
diameter
Hot rolling Large No limit - - No No
Cold rolling Large No limit - - No No
Drawing Smallbarge AI, Cu, Zn, 3 mm/6 m 0.1 No Yes
mild steel diameter
Spinning One-off, Al, Cu, Zn, 6mm/4.5m 0.1 No Yes
large mild steel diameter
Impact extrusion Large AI, Pb, Zn, 6-l00mm 0.1 - No
Mg, Sn diameter
Sintering Large Fe, W, bronze 80g to 4kg 0.5 Yes Yes
Machining One-off, No limit - - Yes Yes
large