The wheels on my Genesis Day One fixed are held on with m6 dome headed Allen bolts 25-30mm long. One of which has been removed and replaced enough times with Allen keys of variable quality that the socket head is now sloppy. Can anybody point me to a source for these bolts please? Local bike shops don't stock them, nor generic suppliers like screwfix. Cap-headed bolts are easy to source; I could use these combined with suitable washers but am looking for a like for like replacement if possible. Best quality would be good. I don't mind buying two or four for future-proofing.
Given the choice I'd prefer proper track nuts, but the Allen bolts perform ok, until worn out, and it seems daft to discard a wheel for the sake of a bolt!
TIA