How To Shorten a Machine Screw or Bolt
|Shortening a small machine screw or bolt is often not a simple as it seems, gripping the head in a vise will likely mark or distort it, and it is often difficult to get it started once shortened. Threading a nut on to the screw or bolt serves two purposes, it gives you something to hold on to in the vise and it reforms the threads as it is removed making it easier to start.|
Using a Hacksaw
Thread a nut on to the screw or bolt so that the outer edge of the nut is where you want to cut it off. Grip nut sideways in vise and tighten enough so that screw will not turn with your fingers. Make your cut, then rotate nut to next flats and squeeze in vise until screw will turn. Turn screw into nut so that three or four threads are showing, grip in vise again so it will not turn and file end at about 45 degrees to a depth of about one thread.
Using a File
Follow above instructions but grip nut flat in vise.
Shortening Larger Bolts
To shorten larger bolts just grip the head in the vise, thread a nut on to the bolt past the cut position, make the cut, file the end then remove nut which will reform the threads for easier starting.