The aluminium sheet and coil surface isn't allowed to have a crack, corrosion and crack edge, the sheets that's more than 0.6 mm thick surface diffusion is not approved in spots.

The floor of the anodised aluminum sheet permits moderate scratches, scratches, scratches, curler marks, pine dents and emulsion marks on metallic surfaces and nonmetallic implants. But, the intensity of numerous defects shall now not exceed the…