Mild scratches can be repaired by basic grinding and sanding, but deep scratches need more delicate repair procedures. As the surface technology of watch case, there are basically two kinds: polishing and frosting, or both. To repair the scratches on the watch case, we should also follow the original process, and it is easier to wear a large area of hair. But if there are deep hard scratches, it will be more troublesome, because neither polishing nor sanding is enough to remove such scratches. Local deep scratches on the watch case or strap should be polished with an oilstone first. This needs to be done under a magnifying glass. The purpose is to smooth out the scratches. When the scratches are basically smooth, choose sandpaper with appropriate granularity and polish it along the original sanding grain. Usually this grain is radial with the dial as the center. Therefore, this is a meticulous work. It takes a little effort to get a good realistic polishing effect. It is recommended that the jewelry industry use sandpaper, preferably imported, such as German Warrior brand water sandpaper. Handheld tools are also exquisite. It is recommended to use surgical hemostatic forceps, only take a small piece of sandpaper, fold it in half and clamp it with hemostatic forceps. Sapphire glass is hard and can be ignored. However, the case of the watch is stainless steel, so you must pay attention to it when operating, and you can cover it with tape if necessary. Technically, all frosted lines should be straight, and they all start from the center of the dial and radiate. In this way, all scratches on the watch case and strap can be removed, or the appearance of the watch can be refurbished. Straight lines are easier to handle. If the line is concentric circles, it still needs to be made by a motor. For cases and watchbands that have both sanding and polishing processes, they should be sanded first and then polished, but only the sanded parts that have been trimmed should be covered. Simple tape can be used, and the formal one will be made into a metal template, which is also used to cover it when polishing.