Firstly, it is explained that the grindstone is a double-sided grindstone (one side is thick and the other side is thin). Hold down the planer with both hands, grind the planer into a 40-degree cross section with the rough surface opposite the grindstone, and pull it back and forth in parallel (the planer and the grindstone form 30 degrees).

Secondly, grind it roughly first, then grind it in a place with strong light until you see a little cutting edge on the edge, and then use a fine grinding stone mill. Finally, just look at the blade carefully and see that there is no sand hole. Or a few scratches on your hand, if you feel Mao Mao's, it means success; If it feels slippery, you must grind it again. Then turn off the lights slowly with the reverse side. (When polishing, be sure to apply force evenly, and then polish it twice with water. )

Never use power tools to polish, or the plane will fade easily, and the faded steel is scrap iron. The planer is best polished with a special tool, about 800 pieces. Hand grinding is not good.