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

[Frank S]

Hi Phillip, I did 2 of the flats then the next 2 because of the way i had to clamp the nuts in the angle vice I had to lower the spindle a bit more to achieve the depth of cut I needed then adjust it one more time to do the remaining cuts. The reason for this was the best reference I had for securing the nuts was to clamp opposing flats and use the corners to keep them parallel, there are many other ways of milling down the flats, but this method was my quickest avenue as it was not overly critical all flats be perfectly concentric. A larger diameter endmill could have cleared the whole face of the flats in 1 pass but I have a limited selection of collets which will fit the mill. The worst thing was the nuts were hardened nuts and I don't have a coolant spray so I have to run at a lower RPM than I care to, to preserve my endmills. There is a huge RPM gap in the speed selection ranges it jumps from 450RPM to 1200 with nothing in between