What is the difference between mill finished aluminum and anodized aluminum

Both are aluminum extrusion technical term and both products are extrusion products in the mill.

Mill finished aluminium means the extrusion products without any surface treatment; it is simple products after the extrusion processing in the extrusion press. The appearance is natural color of aluminum and it is sliver, as without any surface treatment, there will be some die lines and marks on the surface and it is widely used in the inner decoration and inner parts of finished products.

Anodizing aluminum means mill finished aluminum with anodizing process, it is high value added products and the processes in the production will be more, the anodizing color can be matt silver, anodized champagne, anodized bronze, anodized black, anodized gold and some other colors.  It is mill finished aluminum next surface treatment products, the anodizing production will be done in the tanks for the anodizing film, which can increases the thickness of the oxide coating on the aluminium improving its resistance to abrasion.  The anodizing processes can be alkali etching and acid etching; also some extruders make the polishing, sand blasting or shot blasting operation on the aluminum profile before anodizing to remove the die line and scratch.  The anodizing aluminum surface will be smooth and elegant and it is widely used in window and door, curtain wall, industrial profiles and decoration profiles. As anodizing process can make different color, so anodizing aluminum are most popular in the market.