File

A file is a metalworking, woodworking and plastic working tool used to cut fine amounts of material from a workpiece. It most commonly refers to the hand tool style, which takes the form of a steel bar with a case hardened surface and a series of sharp, parallel teeth. Most files have a narrow, pointed tang at one end to which a handle can be fitted.
A similar tool is the rasp. This is an older form, with simpler teeth. As they have larger clearance between teeth, these are usually used on softer, non-metallic materials.
Related tools have been developed with abrasive surfaces, such as diamond abrasives or silicon carbide. Because of their similar form and function, these have also been termed ‘files’.
Archaeologists have discovered rasps made from bronze in Egypt, dating back to the years 1200 – 1000 B.C., Archaeologists have also discovered rasps made of iron used by the Assyrians, dating back to the 7th Century B.C. Among the drawings of Leonardo da Vinci is a sketch of a machine…