Hard Anodizing is typically applied to heavy wear industrial parts intended for use in aggressive or
highly corrosive applications especially when you have sliding parts , and abrasion is an issue. These coatings
are typically far thicker and harder than decorative ones, and usually lend the parts a durability approaching that
of hard faced or case hardened steel.
Hard coated items usually have a dark gray to a black finish. This can vary depending on the aluminum alloy.
One of the main purposes of hard anodizing is to make the aluminum more resistant to corrosion. The thicker
oxidized layer protects the finished part from being exposed to moisture, oxygen, and other factors. Sealed items
are even more corrosion resistant. These coatings are UV stable and are only available in clear an black.
The outer coating is also extremely hard, typically much harder than the original metal. In many cases, a thick
hard anodized coating can be as hard as tool steel.
The oxide layer is part of the metal, it won't peel off and the surface finish will increase.
Hard anodized metals are usually very well insulated they don't conduct heat or electricity well.
This is especially useful for applications that require the part be used at high temperatures.
Typical hard anodizing applications are for hydraulic cylinders, forks, any exterior grade aluminum and surfaces
that require abrasive or scratch resistance such as marine, aircraft, & auto parts.