About Product:The quality of this product is guaranteed, and the price is favorable. The factory directly sends these files according to the plane to be processed: Triangular file is used to file the inner corner, Triangle hole and plane; Four-corner File (square file) it is used to file square holes, rectangular holes and narrow planes; Semicircle file is used to file concave arc surfaces and planes. file, also called file, steel file, is a manual tool. Strip, multi-blade, mainly used for micro-processing of metal, wood, leather and other surface layers. According to different cross sections, it can be divided into flat file, round file, square file, triangular file, Diamond file, semicircle file, knife file, etc.