Machining an AR15 lower receiver

[Highpower]

(06-21-2012, 10:30 PM)Mayhem Wrote:

I have heard that the hard coat anodizing requires the parts to be slightly under sized, to allow for the thickness of the coat. I'm curious as to ho this affected (if at all) your build.

I had heard that as well Darren. But after researching it a bit, most of what I read stated that half of the conversion was below the surface and half was on top of the surface. I saw numbers between .0005" to .002" for the depth of the change. So I took a leap of faith and made a SWAG, and cut the internal walls .001" over the specs I had.

I got REAL lucky because it turned out to be spot on. Had another shop done the anodizing, it might have been totally different - I don't know. I think a great deal depends on the amount of current used and the length of time they spend in the tank.