Files 

Files come in many shapes, sizes and degrees of coarseness. The main function of a file is to remove a small amount of material through an abrasive motion. Files are very hard and brittle. If you drop one on the floor it may break. The file has to be hard to hold an edge to cut with. The file is not a substitute for a saw. Many times it is used after a saw to form irregular shapes or rough out a shape.