Composition of metal plate on Bottlehead hardware?

[CowboyBebop]

Can anyone tell me what the metal top plate on my Mainline is actually made out of exactly? I think it's Aluminum, but not sure. And if so, is there a specific composition? Asking because I'm looking at getting it anodised and they want to know a lot of details about the metal.

[Paul Birkeland]

They are 5052 aluminum. 

[Deke609]

Just raising this in case it is a cause for concern. I've read that the resulting oxide coating from anodizing is electrically insulating. I wonder if this might negatively affect the grounding scheme, and most importantly, the safety grounding scheme of the amp.

cheers, Derek

[Paul Birkeland]

You just want to make sure the hardware is really tight.