By Bob Daley
I was recently making some special C-clamps, cut from 2” long, 1/8”thick hot-rolled steel, and planned to use 4 mm screws, 8 mm long with them. The screws needed to have the end square to the axis (approximately) and smooth, with the end beveled for easy starting in the clamps. I purchased the screws only to find the ends were not my liking. I tried to file the end but found it difficult to hold the screws (a difficulty often encountered when cutting long screws to a shorter length).
Then a thought hit me: If I took one of the C-clamps and drilled a 17/64” hole in the end opposite the 4 mm tapped hole I could poke a Phillips screwdriver though the hole and use it to locate the screw in the tapped hole.
With this setup, I was able to file the screw ends square by advancing the screw just through the clamp, using the face of the clamp to keep the file square. Then, by turning the screw with the driver was able to bevel the end nicely.
I now have a novel way to true up screw ends that have been cut with a saw, etc.