it's not the axle/track nut on the outside, but the locknut/washer that rests against the inside of the dropout/fork end. it seems they're stamped, which may be intentional to avoid bearing damage from overtightening, but i think i just forgot to snug it down last time i took off/put on the wheel. anyway, the other side has one i got from the lbs, but it's a slightly different thickness and diameter and has no wrench flats like the stock piece. (although maybe i just have to find something similiar seeing as that one hasn't snapped)