Aim Surplus AR Foundation Kit

[Slippers]

All anodizing does is align the surface molecules of either the machined billet block or the forged block after it's been machined in order to provide surface hardness to generally 1/10,000th of an inch.

Hard coat anodizing, which is basically what all parts are done with in the firearms industry, is much thicker. A good anodizer lets you specify the thickness, which is normally one or two thousandths of an inch (not ten-thousandths), with half being buildup on the outside of the part, and half going into the aluminum. This is very important because the tolerances on each part can change significantly. The fact that it builds up into the aluminum is also why it's so durable.

Anything you see that isn't black, elephant gray (6061 with no dye), or light bronze (7075 with no dye), is probably not hard coat, and will not be very durable. All those little magazine releases in rainbow colors are not hard coat anodized, for instance.