As extrusion is a forming process, this category applies to the extrusion process only, without any design, secondary operations or assembly completed by the extrusion supplier.
The first step in the process is to create a die resembling the desired cross-sectional profile of the extrusion - alternatively this can be free-issued to the supplier if tooling already exists.. The die is mounted to one end of an extrusion press, whilst the material is placed into the cylinder and forced through the die by a piston. Depending on whether a hot or cold extrusion process is being used, the material may be heated, or kept at room temperature.
As the material is forced out of the die, it takes on its profile, meaning that long lengths of extruded material can be created with cross-sectional symmetry. These are then cut to the required length.
Secondary operations such as finish machining or surface treatment may still need to be carried out to ensure that the extruded components meet the required specifications.