Question: How to shape an old sawzall blade into a knife blade.
Option 0: Hold the sawzall blade by the back edge and carefully grind off all the teeth with a belt grinder. Hold the blade at a 20 degree angle and sharpen one side, flip over and sharpen the other side.
Option 1: Hold the sawzall blade by the back edge and carefully grind off all the teeth with a belt grinder. Hold the blade at a 90 degree angle and sharpen one side, flip over and sharpen the other side.
Answer: 0