Shimano Dura-Ace stem

[SeeingisBelievingGTMuseum]

Uses of all things a 7mm allen/hex wrench....not always an easy one to find.

 

[rayms]

Re:

I've just taken this off a 600 AX. The coarse thread is left handed. The wedge swivels on the narrower part and is held on with the nut.

I picked up a 600AX recently and its 335 grams!
In this pic the bolt looks duller, appearing alloy and mine is steel but that would not account for a small fraction of the 75 grams difference.