Page 335 - Manufacturing Engineering and Technology - Kalpakjian, Serope : Schmid, Steven R.

Part III Forming and Shaping Processes and Equipment 3 I 5

TABLE lll.l

General Characteristics of Forming and Shaping Processes
Process Characteristics
Rolling
Flat Production of flat plate, sheet, and foil at high speeds; good surface finish, especially in cold
rolling; very high capital investment; low-to~moderate labor cost
Shape Production of various structural shapes (such as I-beams and rails) at high speeds; includes
thread rolling; requires shaped rolls and expensive equipment; low-to-moderate labor cost;
requires moderate operator skill
Forging Production of discrete parts with a set of dies; some finishing operations usually required;
usually performed at elevated temperatures, but also cold for smaller parts; die and equip-
ment costs are high; moderate-to-high labor cost; requires moderate-to-high operator skill
Extrusion Production of long lengths of solid or hollow shapes with constant cross section; product
is then cut into desired lengths; usually performed at elevated temperatures; cold extrusion
has similarities to forging and is used to make discrete products; moderate-to-high die and
equipment cost; low-to-moderate labor cost; requires low-to-moderate operator skill
Drawing Production of long rod and wire with various cross sections; good surface finish; low-to-
moderate die, equipment, and labor costs; requires low-to-moderate operator skill
Sheet-metal forming Production of a wide variety of shapes with thin walls and simple or complex geometries;
generally low-to-moderate die, equipment, and labor costs; requires low-to-moderate
operator skill
Powder metallurgy Production of simple or complex shapes by compacting and sintering metal powders;
moderate die and equipment cost; low labor cost and skill
Processing of plastics Production of a wide variety of continuous or discrete products by extrusion, molding,
and composite materials casting, and fabricating processes; moderate die and equipment costs; requires high
operator skill in processing of composite materials
Forming and Production of discrete products by various shaping, drying, and firing processes; low-to-
shaping of ceramics moderate die and equipment cost; requires moderate-to-high operator skill