SloopJohnB@mac.com

I'll give him the benefit of the doubt that he's not necessarily meaning a harder bolt or a bolt with a different Young's Modulus.

SloopJohnB@mac.com

Or worse, you end up with a bolt with inadequate stretch and find yourself in a situation where material relaxation due to creep or temperature change eliminates the stretch and the bolt goes loose. With the UCAs it might not matter so much as long as the bolt stays in there because the BJs are held in with a notch/smaller OD in the BJ post that the pinch bolt goes through/by. Still..

socalclimber

I agree with all posts, get the dealer bolts. You are never going to match that caliper bolt from other sources, it has a special collar and maybe even an integral washer.

I looked up 2000 A6 4.2 in my ETKA and front caliper bolt is N90876801 and it is a M14x1,5x38 and says "bolt hex head w/ shoulder".

At guineaudiparts.com (a good online Audi dealer in San Diego, CA), this bolt has been superceded to N90876802 and costs $4.09, a great price!

I buy my dealer parts from guineaudiparts.com as they usually have the best prices. For comparison, ECS Tuning has this same bolt for $6.60.

I bought from guineaudiparts.com all new rotors and caliper bolts, front and rear, when I did my brakes with Akebono pads. Their web site has been re-done, and it's harder to find parts there now, but they have great email service, and will get you the parts you need, they usually need your VIN to confirm P/N's.

Do yourself a favor, get the dealer bolts!