Cutting Through Threads so They Still Work
by Damien Andrews
If you've been a do-it-yourselfer for more than about a month, you've likely encountered one of life's seemingly insurmountable little problems. You've cut back a bolt, and can't get the nuts threaded back onto it.
It seemed like a simple thing to do. You have some ¼" nuts, washers and bolts – but the bolts were 4" long, and your job called for ones that could be no longer than 3". Out comes the hacksaw, and the first problem arises: stabilizing the bolt while you cut it down. After you figure your way over that bump in the carpet of your task, the real problem hits you – you can't get the nuts back onto the freshly pruned bolt. If you're like most do-it-yourselfers, you take the trimmed bolt, a small file, some emery cloth, and perhaps an awl – and you start to 'clean-up' the burry end of the bolt. This futile adventure can last as long as you want – in case you gave up after only an hour or two.
Cutting through the threaded part of a bolt so that they nuts will still screw on and off easily is really a very simple thing to accomplish. Refer to Diagram A.
Before cutting your bolt, screw two nuts onto the bolt. Continue to screw the nuts on until they are above the point where you want to make your cut. The addition of the nuts will provide more surface area for your vise or clamps, so holding the bolt against the torque of cutting it is now no longer a problem. Now go ahead and, using either a hacksaw or bolt cutter, cut the bolt where you want.
After the bolt is cut, use a fine or medium metal file to very lightly, very gently file of any excess metal off of the rim of the cut. You are only interested in removing any larger pieces. Now remove the outermost nut from the bolt. When it gets to where the cut was made, it will be a tad more difficult, but continue on. Once the first nut is removed, again take your fine or medium metal file and trim any excess away from the edges of the cut. When that is done, unscrew the second nut until its threads on ARE on the cut. Twist the nut back and forth/on and off several times – without actually removing the nut from the bolt. You want to make sure all the bad parts of the cut area are gone now. When you're through with this step, the nut should twist freely right on the cut edge.
Finally, take some emery cloth and lightly buff up the freshly cut edge of the bolt. Your nuts will now always easily slip on and off of that bolt.