Awhile back I noticed one of my suppliers sold a hexagonal bar stock. I did not pay it much mind until I bought a local fabricated hose nipple that was made from that bar stock. The hexagon bar formed the nut that the wrench gripped. So it has me thinking. I have a lathe available with a 4 jaw chuck. If I put the hex nut off center, used a drill with a chuck in the tail stock, Then centered the now drilled bar to chamfer and part... A one foot length of half inch hex rod is only a couple dollars. The rest is machine time... Am I on the right track?