What is a file?
A file is a length of metal with teeth cut into at least one of its sides that is used for shaping or finishing (smoothing off) a piece of material.
Files can be used to remove unwanted sharp slivers from a piece of metal that are left along its corners after it has been cut or sharpened. This process is known as 'deburring'.
They are most often used in metalworking, but have also been developed for use on wood, plastic and composites (such as glass-reinforced plastic or the metal compound used in tennis rackets).
Depending on the arrangement of their teeth, files may also be referred to as 'rasps'.
For more information on file teeth, see:
Files are also used to sharpen other tools such as saws and knives.
Precision crafting trades, such as locksmithing and watch making, use files for precise finishes on small parts.