1. According to the purpose, there are: ordinary fitter files, used for general filing processing; wooden files, used for filing soft materials such as wood and leather; plastic files (assorted files), used for filing small and fine metals For the parts, there are many files of various cross-section shapes to form a set; files for sharpening woodworking saws; special files, such as flat and arch shaped files (special files) for repairing special shapes, including straight and curved files.
2. Files are divided into flat files (flat files), square files, semicircular files, round files, triangle files, diamond files and knife-shaped files according to their cross-sectional shape. Flat files are used to file flat surfaces, external circular surfaces and convex arc surfaces; square files are used to file square holes, rectangular holes and narrow flat surfaces; triangular files are used to file internal angles, triangular holes and flat surfaces; semicircular files are used to file concave arc surfaces And flat surfaces; round files are used to file round holes, concave arcs and ellipses with smaller radius.
3. Files are divided into single-grain files and double-grain files 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 secondary file patterns of the double-grain file are arranged in a crossed arrangement, which is used for processing steel and non-ferrous metals. It can divide wide filings into many small sections, making filing more brisk.
4. The files are divided into No. Ⅰ ~ Ⅴ according to the number of main file lines per 10 mm length, among which No. Ⅰ is coarse-tooth file, No. Ⅱ is medium-tooth file, No. Ⅲ is fine-tooth file, and No. Ⅳ and Ⅴ are glossy Files are used 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.
