Grinding And Sharpening: In metalworking, sandpaper might be used for grinding and sharpening various metal instruments and surfaces. Coarser grits, like 36 or sixty, are used to remove material and shape the steel. This is very helpful for reshaping or sharpening blades, chisels, or other cutting instruments. Added Fantastic Grits https://x.com/hongyuxin20/status/18174338060199814309