[pugs]

I agree, if doing aluminum 6061 is probably best bet. Depending on cost, I would probably opt for hard anodizing to get some wear resistance at least for the track pads. Not sure how my anodizer would like that many tiny parts if doing the links though.

Now if went carbon steel it should be pretty good for wear on the pads, and pretty easy to black oxide all the pieces for a good look.

If you get your design finalized and want a couple more prices ask Dan and I for quotes.

One thing I notice in the pic you posted of your design so far. I see a thicknees bump out in the links around the pad bolt holes. That will add to machining costs, more so than just making the whole link thicker. Same for what looks like a raised boss around where the pins go through, but it may be e-clips, hard to see for sure.