You can depend on the features as following:
1, The thickness of aluminum case body
Usually, a good aluminum box with a thick plates. 1.2mm below the material bearing, bending performance will be discounted, especially the material below 1.0mm, the surface is easily deformed because of bumps, so the high quality aluminum shell is generally very thick.
2, Surface treatment of the aluminum products
Anodizing is to clean, oxidize, coloring and sealing the aluminum profile products in the oxidizing bath liquid. The alumina thin layer is formed on the surface of the aluminum product. Its thickness is 5~20 microns, which can effectively improve its hardness and wear resistance. However, because of the change in the chemical composition in the bath liquid per batch of aluminum oxide, it is oxidized and coloured. The aluminum material that comes out always has a color difference.