The drawing of the wire drawing die shows that the die has been worn and needs to be polished again. If the die is round, the female die can be clamped on the lathe and polished with oilstone and polishing paste. If the mold is not round, only manual grinding and polishing can be used. Tools for grinding and polishing include oilstone, metallographic sandpaper and diamond polishing paste. The principle of grinding and polishing is coarse first and then fine. That is, first use coarse oilstone or sandpaper to polish, then use slightly finer oilstone and sandpaper to polish, and finally use metallographic sandpaper above 1000# to polish. If it is necessary to polish the polished mirror surface, polishing paste with a particle size of W3.5 can be used to polish it to the mirror surface.