A question about your nuts...

[blacktiger]

Disc bolts are fine to re-use so long as you torque them correctly and locktite them in.

[Sin_Tiger]

I don't mind re-using bolts I've ridden with and removed myself. I would NEVER buy used disc bolts though 

[Bixxer Bob]

Ditto!

[London_Phil]

More likely to fubar the head getting them out...

[ssevy]

Sorry for the really late comment, but since folks dig up these older threads while searching...

I often use a dab of grinding compound on the tips of bits and screwdrivers when trying to get out fasteners that I know will be apt to round out. For an allen head, I put it just on the sides and not the tip, so that when I tap it in with a hammer it fully seats. The micro grains of the compound seem to bite into the surfaces of the flanks of the bit/fastener while taking up that really tiny gap that lets the bit bypass the flanks and run out. The careful tapping in of the bit with the hammer is absolutely key to the whole endeavor.

[Madruss]

Great information once more.