Extruding

The extrusion process forces hot metal through a shaped die to produce circular, rectangular, tubular, angular, half-round sections etc.

In some respects, the process is similar to drawing, but extruding forces metal from a heated billet, through hardened dies by compression. Whereas, in drawing, it is achieved by tension. Therefore, malleability is an essential material property for the extrusion process.

Extruding is normally restricted to aluminium alloys and copper alloys, where extrusion temperatures of 400ºC-500ºC and 650º-1000ºC, respectively are used. Steel is extremely difficult to extrude, due to the excessive pressures required.