A file is a hardened steel tool with cutting ridges for
forming, smoothing, or reducing, especially metallic surfaces. Files are
classified by their length, type and shape. Quality is determined by
lasting performance and cutting ability. Length is measured from the
point, i.e., the square end of file to the shoulder, where the blade
sets onto the tang. Length indicates coarseness, stroke distance and
rate of stock removal.
The files may be square, round, half-round, flat etc., in shape. The
file may be taper or blunt in shape. As their names imply, taper files
taper from shoulder to point while blunt files are the same width for
the entire length.
File cut is determined by coarseness and character of teeth. Four basic
cuts are as follows:
- Single Cut: Single cut denotes a single row of
chisel-cut teeth. These files are used on saw teeth and metals where
a good finish is required.
- Double Cut : Double cut, used primarily on metals where
rapid stock removal is necessary and a rough cut is permissible, has
two rows of chisel cut teeth.
- Rasp Cut : Rasp cut, used on soft metals and wood for
rapid stock removal, has individually punched teeth that are
entirely separate from each other.
- Curved-tooth Cut : This type of cut features teeth that
are milled in an arc. This cut is used on flat surfaces of soft
metals for rapid stock removal and a fairly good finish.
File teeth are further divided into four groups such as:
- Second and
Coarse and bastard cuts are used on heavy work, while second and
smooth cuts are used for finishing or more exacting work.
Types of files
- Saw files: Saw files are used for filing all types of
saws with 60° angle teeth. Single cut edges set and cut for
filing gullets between teeth. Saw files are available in several
grades. It is important to select the right file for the right
handsaw. Two types of saw files on the basis of their cut sides are:
- Single Cut Sides: For hand filing.
- Double Cut Sides: For Use on saw Filing
- Machinist file Machinist files are used for stock removal
and surface finish requirements on machined components. The
machinist steel files and flat steel files are generally used in
mechanic and locksmith works. Also known as Engineers´ Files,
Machinist Files are generally split into two types of different
Machinist files may come in different shapes such as Hand,
Flat, Three Square, Square, Half round, Round & Knife shapes,
Magneto Files, Farmers Own and Mill Files.
- Double Cut: It is used for rapid stock
- Single Cut: These are also known as Saw
Files and are used for sharpening.
- Chain Saw Files: Chain saw files are meant for saw chain
and also used to clean and dress up gullets of some saws. Chain saw
files are made for both round-hooded and square hooded chain saw
teeth. For the former, the file must be held level against the bevel
of the cutting surface of the tooth at an angle of 25° to 45°,
with the saw blade. File direction is off the cutting edge, pressing
back and slightly up during the stroke. When using a square chain
saw file (lozenge shape), the file is placed under the hood so two
adjacent sides of the file contact both saw-tooth edges at one time.
In both cases, depth gauges should be filed to maintain the required
difference in height from the cutting teeth. A flat-side single-cut
file is used for this. Some chain saw files feature a molded-in
filing angle indicator to make uniform sharpening easier.
- Diamond files: The peculiarity of diamond files is that
they have small diamond particles embedded in their surface. The use
of diamonds allows the file to be used effectively against extremely
hard materials, like glass, stone, hardened steel against which a
standard steel file is ineffective.
- Riffler files: Riffler files are available in a
collection of different shapes and profiles ranging from small to
medium size. The various shapes and profiles help them to be used in
hard to reach or unusually shaped areas. They are often used in die
making when the surface finish of a cavity die requires improvement.
- Needle files: Needle files are also available in sets of
6 or 12 or more different shapes. They are small sized files used in
applications where the surface finish is more important over metal
removal rates. They are suited for small work pieces.