reducing the wrench size on 5/8-18 hardened jam nuts

[Frank S]

I needed to reduce the wrench size on some 5/8" fine thread jam nuts due to a space limitation issue on a project I am working on
I thought of boring out some 9/16" nuts then re threading them but didn't have but 2 of them also they were 7/8 across the flats I wanted to go smaller than that since the 5/8 nuts take a 15/16 wrench, and I didn't even think of using half inch nuts boring and threading them until after I had milled the ones I had. OH well next time as they say.
I milled the flats down to accept a 13/16" wrench