Cold Extrusion

Cold Extrusion

Developed in the 1940s, cold extrusion is a general term that often denotes a comb¬ination of operations, such as direct and indirect extrusion and forging (Fig).
Cold extrusion is used widely for components in automobiles, motorcycles, bicycles, and appliances and in transportation and farm equipment.

This process uses slugs cut from cold-finished or hot-rolled bars, wire, or plates. Slugs that are less than about 40 mm (1.5 in.) in diameter are sheared (cropped), and if necessary, their ends are squared off by processes such as upsetting machining, or grinding. Larger-diameter slugs are machined from bars into specific lengths. Cold-extruded parts weighing as much as 45 kg (100 Ib) and having lengths of up to 2 m (80 in.) can be made, although most parts weigh much less. Powder-metal slugs (preforms) also may be cold extruded.