Well, it's actually very simple. If your workpiece is not too thin, measure how much allowance is left after exposure on both sides, and then directly cut the knife to leave 10 pieces, generally not more than 2MM (more than the sliced pieces are cut off), and then build a coarse grinding wheel platform to polish off the burned two sides of the handle, and leave 5 pieces in place. If it is very thin, pay attention to deformation, but if the workpiece is not too big, you can knock it back with a copper rod. In fact, the most important thing is yourself.