[TheForge] bolt thread repair tool

[Steve Bloom]

On Feb 24, 2015, at 8:50 AM, David E. Smucker <davesmucker at hotmail.com> 
wrote:
> I know of no personal history on a vise repair of this type but very large
> power screws for rolling mill have been made for many many years with a
> steel screw and a bronze nut.
[snip]
Just another datum. One of my students wanted to explore building a post 
vise. She used a lathe to cut a 1.5" acme shaft and then created the nut 
with an internal threading boring tool.  I though that there might be an 
"easier" way.  I winded up wrapping 3/16" square stock around a 1.5" 
diameter scrap of acme threaded shaft. The resulting coil was screwed 
off the shaft and inserted into a 6" piece of pipe that had 8 narrow 
windows milled along the length (each about 1/4" x 3"; each set of 4 was 
rotated 45 degrees relative to the other set). The coil was tacked 
welded to the sides of the slot where every I could.  The screw was 
installed in a vise made of 3" channel (the cavities to the interior).  
In use, the screw bend the channel without failure of the screw or 
"nut".  Of course, the true nut was me for doing all of this instead of 
just buying a post vise <grin>

Steve