I need to machine up some mounts for wilwood powerlites. Due to the lug mounts on the uprights and the radial mounts on the calipers sharing fixing centres I will have to tap the radial mounting bolts into the alloy adaptor. These will be tpped to a depth of about 20mm on an M10 thread.

Can anyone tell me what grade of alloy bar I should be using (need 20x40 bar) and also should I helicoil it ( only 1.5 times dia deep iirc) and am I best to use standard or fine pitch bolts? Fine is better for torquing up, but caure pitch might take a better thread in the aluminium?

Cheers

no one?

6082 T6 /HE30 would be Fine, easy to machine as well.
Standard pitch in alloy, if you need fine then helicoil would be a must.

[Edited on 30-5-09 by 40inches]