Left-Handed Screws
A screw plate for left-handed screws can easily be made by screwing a good piece of steel of the desired size into a right-handed screw plate, removing, filing down on two sides, to leave only a knife edge, and hardening. Drill hole in steel plate and cut with the screw described by turning with reverse or left-handed motion. Left-handed screws can be made very successfully with this plate.