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

[DIYer]

Thanks Frank S! We've added your Wrench Size Reduction for Jam Nuts to our Fastening category,
as well as to your builder page: Frank S's Homemade Tools. Your receipt:

Wrench Size Reduction for Jam Nuts by Frank S

tags: wrench

[Philip Davies]

I have never done milling, Frank. I am curious to know whether you used just one depth setting. Or did you use two parallels under the 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

[Toolmaker51]

Tilt vises are boat anchors; until you need one.
Tilt/ swivel/ probably good for battle ships.
Tilt/ swivel/ compounds, the largest tankers.

Still heavy but what a saving by way of convenience. And not re-tramming the head.

[Frank S]

Tilt vises are boat anchors; until you need one.
Tilt/ swivel/ probably good for battle ships.
Tilt/ swivel/ compounds, the largest tankers.

Still heavy but what a saving by way of convenience. And not re-tramming the head.

When you have a stiff head mill, tilt/swivel vises gain value real quick, and IO can think of times when having the addition of a compound on it could be handy but rarely
A place I once worked at had a 50 hp Cincinatti stiff head vertical mill which had a huge compound swivel tilting vise mounted on an adjustable angle fixture pretty much permanently mounted on 1 end of the table, and a 30" rotary table mounted on the other end.