Extrusion is a process used to create objects of a fixed, cross-sectional profile. A material is pushed or drawn through a Die of the desired cross-section. The two main advantages of this process over other manufacturing processes are its ability to create very complex cross-sections and work materials that are brittle, because the material only encounters compressive and shear stresses. It also forms finished parts with an excellent surface finish. The extrusion process can be done with material hot or cold.
Commonly extruded materials include metals, polymers, ceramics, concrete and foodstuffs.