type 3 part kits

Question
I am looking at an ak-47 parts kit. It is advertised as type 3 parts kit. says it is a milled russian/hungarian reciever. My question is pretty simple, what is a type 3 parts kit exactly?

Answer
Travis,

Type 3 or more properly Type III refers to the anodized coating on the parts.  There is a military specification that states that an anodizing coating must be of a certain thickness to qualify as Type II (.001" to .006") or Type III (greater than .001")

Most parts manufacturers for AR or AK variants manufacture their upper and lower receiver kits to this specification.

Aluminum alloys are anodized to increase corrosion resistance, to increase surface hardness, and to allow dyeing (coloring), improved lubrication, or improved adhesion.

That's it...hope this clarifies for you.

Cheers,

Doug