Any time you grind and polish stone by hand, you use sandpaper with grits of different coarseness. Sandpaper has quite a few uses while in the Do it yourself sector, but its Main use will be to condition and smooth tough edges and surfaces on numerous things made of wood, https://www.quora.com/profile/Trevor-Flatcher-2/Key-Applications-of-Silicon-Carbide-in-the-Aerospace-Industry-Silicon-Carbide-SiC-has-emerged-as-a-crucial-material-i