A file is a tool mainly used in locksmithing. Files are used for smoothing or grinding surfaces or edges. The working surface of the file has notches, which my vary in order and size. Depending on the cross-section of the working part, locksmith files can be divided into:

• flat files,
• square files,
• triangular files,
• Round and half-round files.

In addition to hand files, there are rotary shank files that attach to power tools such as drills or straight grinders.