How to select a file that fits your needs.
Based on the use
Regular, "workshop" files
For run-of-the-mill tasks that do not require extreme precision – from common house repairs to locksmith workshops. All of these are double-cut. The shape and grit need to be selected according to their intended use. The rule of the thumb is that the grittier the file, the more material it files away. The smoother you need the finish, the finer must be the file.
Similar to workshop files. They tend to be used for fine filing and polishing and are also double-cut. To file to the finest detail, they are tapered.
These are used to repair saw blades. Saws featuring hardened teeth cannot be sharpened using a file. The files can be used, however, to sharpen other tools.
These files are mainly used by engravers, locksmiths, horologists, tinsmiths, jewellers, toolmakers… All come double-cut and at 140, 160, 180 or 200 mm.
These files are cut on both ends while the middle section is smooth, uncut. They are used to file in hard to access places to make tools or moulds. They come either at 150 mm (thin gravers) or at 180 mm (thick gravers).
For shaping wood – ideal for modellers or carpentry enthusiasts.
Various grit numbers suit various needs. Grit should be selected based on the filed material, the required amount of material filed with each stroke and the fineness of the material.
The coarseness of files is defined as the number of cuts per centimetre of length.
(see fig 1).
The coarseness of rasps is defined as the number of cuts per centimetre squared.
(see fig 2).
Numbers of cuts on files and rasps as defined in DIN 8349
Size of the files in tables is defined in terms of teeth (cuts). The files are crafted in compliance with DIN and ISO standards.