Types of files

Files are classified

1. According to the size of the file

Size is the distance from heel to the point without tang. Files are available in sizes ranging from 4'' to 16''

2. According to the cut of teeth

Cut of teeth is the type of arrangement of teeth of the file which may be Single cut, Double cut, Rasp cut or curved cut.

Single cut files have only one set of teeth (over cut) and suited to work on soft metals like aluminium, copper, brass etc. as it has more chip space. It is also used for draw filing on steel plates.

Double cut files are the most commonly used file which has two set of teeth (over cut and up cut) as shown in figure. Over cut teeth is 65degree to 70 degree to the axis of the file with more deep and more spacing between teeth. Up cut teeth is 45 degree with less deep and less spacing between teeth.

Double cut files are suited for finishing work on steel surfaces.

Rasp cut and curved cut files are used to work on non metals like rubber, wood etc.

According to the grade of teeth

Grade or roughness of the file is decided by the space between teeth. Smoothness of the file increases as the spacing between the teeth reduces. Available grades of file is written below in the order of rough to smooth.

Rough, Bastard, Second cut, Smooth, Dead smooth

Rough files are selected to work on soft metals and for roughing operation and vice versa.

According to the shape of the file

Files are available in different cross section to suit to work on different profile shapes. They are, Flat file, Hand file, Square file, Round file, Half round file, Triangular file and Knife edge file.

Special files

Needle files are the small files without handle and are available as sets of all shapes. It is used to work on small corners and openings for precision fitting work.

Diamond needle files coated with diamond powder are used when it is required to file on hardened steel surfaces.