1. According to the purpose, there are: ordinary fitter files, used for general filing processing; wood files, used for filing soft materials such as wood and leather; plastic files (assorted files), used for filing small and fine metals Parts, there are many files with various cross-sectional shapes to form a set; files for sharpening woodworking saws; special files, such as flat and bow-shaped special-shaped files (special files), which are straight and curved.

2. The files are divided into flat files (flat files), square files, semi-circular files, round files, triangular files, diamond-shaped files and knife-shaped files according to the cross-sectional shape. Flat files are used to file flat surfaces, outer circular surfaces and convex curved surfaces; square files are used to file square holes, rectangular holes and narrow surfaces; triangular files are used to file inner corners, triangular holes and flat surfaces; semicircular files are used to file concave curved surfaces and flat surfaces; round files are used to file round holes, concave arc surfaces and elliptical surfaces with smaller radii.

3. The file is divided into two types: single-grain file and double-grain file according to the file pattern. The teeth of the single-grain file are inclined at an angle to the axis, which is suitable for processing soft non-ferrous metals; the main and auxiliary files of the double-grain file are arranged in a cross, and are used for processing steel and non-ferrous metals. It can divide wide filings into many small segments, making filing easier.

4. The files are divided into Nos. Ⅰ～Ⅴ according to the number of main file lines per 10mm length, of which No. Ⅰ is a coarse-toothed file, No. Ⅱ is a medium-toothed file, No. Ⅲ is a fine-toothed file, No. Ⅳ and No. Ⅴ are glossy Files, for roughing and finishing, respectively. The diamond file has no file pattern, but a layer of diamond powder is electroplated on the surface of the file to file hardened metal.