To extrude an aluminum profile a die is needed. This steel die is based on a technical drawing from the customer. The die is resistant against high oven temperatures 

There are two main classes of profile - solid and hollow:

• Solid profiles are produced using a flat, disc-shaped die
• Hollow profiles are produced using a two-part die.

The mandrel, the part that shapes the cavity, is supported on a bridge, around which the metal flows during extrusion. The outer part of the die shapes the outside of the profile.

Large and medium-sized profiles are pressed through a die with only one aperture. 

Smaller profiles can be pressed through multi aperture dies with as many apertures. 

Large and medium-sized profiles are pressed through a die with only one aperture. Smaller profiles can be pressed through multi aperture dies with as many apertures. 
Die lifetime depends on the shape and desired surface quality of the profile.

Extrusion is a deformation of a billet into the profile through the die. 

After the development of the die the first trials can start. When those are tested and approved, the serial production can start.

This is done in following steps:

• heating of aluminum block or "billet" up to 450 ° c
• pressing of hot billet through the die
• air or water cooling of the profiles from 530 ° c to <250 ° c
• supply on the bench to stretch the profiles 
• transport to the end saw
• aging in tank scale after thorough check
• heat treatment in oven to harden 
• measurement hardness (Wb) ~ tensile strength (Rm/Rp) 
• additional control of the profiles