Different hardness. Assorted files are low, and diamond files are high. In mold manufacturing, it is used to repair and decorate the molding part, machining gap or mating surface of the mold. Before the workpiece is touched by fire, you can use a assorted file, which has a large cutting amount, but you can't use a diamond file, because the powder on the file will be greasy. The hardness of the workpiece after fire is high, and the cutting amount using diamond file is small.