I have a 660 u shars vise, (Kurt knockoff) I believe, the screw is tight at spots in the vise nut, does anyone know if a tap is available to clean the threads in the vise nut? I called shars and they dont have or sell a tap for this purpose (1.0625 x 7 tpi), I think this may be an OEM tap.

I can clean it up with a rotary wire brush, this will work for a period of time, then it will start to get tight spots in it again over a few months time.

I would like any advise on any method that would fix this problem .

thanks in advance!