① According to the purpose, there are: general locksmith file, which is used for general filing; Wood file, used for filing soft materials such as wood and leather; Plastic file (assorted file) is used to file small and thin metal parts, and a set of files with various cross-sectional shapes; Knitting file of woodworking saw; Special files, such as flat and arched special-shaped files (special files), are straight and curved. . Triangular file

② Files are classified into flat files (flat files), square files, semi-circular files, round files, triangular files, diamond files and knife files (see figure). Flat file is used for filing plane, cylindrical surface and convex arc surface; Square file is used to file square holes, long square holes and narrow planes; Triangular files are used to file internal corners, triangular holes and planes; Semi-circular file is used to file concave curved surfaces and planes; Circular file is used to file round holes, concave cambered surfaces with smaller radius and elliptical surfaces. square file

③ Files can be divided into single files and double files according to file styles. The cutter teeth of single file are inclined at a certain angle with the axis, which is suitable for processing soft non-ferrous metals; The main file and the auxiliary file of the double-edged file are alternately arranged, and are used for processing steel and nonferrous metals. It can divide a wide file into many small pieces to make the file lighter. round file

(4) Files are divided into I ~ V numbers according to the number of main file lines per 10 mm length, where I is a coarse file, II is a medium file, III is a fine file, and IV and V are smooth files, which are used for rough machining and fine machining respectively. The diamond file has no file, but a layer of diamond powder is electroplated on the surface of the file, and the hard metal is filed with a shaping file.