A file is used to cut, trim or finish a job of metal or wood, in order to give them a shape according to our needs such as making the job round, square or angular. The file is made from high-carbon steel. The file is a hard steel instrument with numerous cutting points. Metal is cut into small or tiny particles with the help of a file. Therefore, mostly a file is used for giving final finishing touches to a job of metal or wood.
1. Classification According to Shape
Following are the different types of file tools according to their shape
1. Flat File
This file is of the rectangular cross-section in shape. It is made slightly tapered both in width and thickness. Double cut teeth are cut on the face and simple cut teeth are cut on the edge. These are used to reduce flat surfaces by the filing of finishing.
2. Round File
This type of file has a round section. It is used for rubbing or finishing keyhole of small diameter.
3. Half-round File
It is a file that is on the side and curved on the other side. Double cut dents are cut on it and like a round file, it is also tapered. With this file, the damaged hole can be set in order again.
4. Triangular File
It is triangular in shape. Its angles are 60°. Filing of “V” slots job, square and rectangular jobs of above 60° and below 90° angle are done with this file. It is also known as three square files.
5. Square File
It is square in shape and is somewhat tapered. Filing of rectangular, square groove, slots, and key-way is done with this file.
6. Hand File
This file is almost similar to the flat file. It is used for filing the internal right-angle side of a job. It is also called a safe edge file.
7. Knife Edge File
Its shape is like the edge of a knife. Its thin edge is about 10° angle. It is used for filing small grooves and slots whose angle is less than 60°. It is generally used in the lock industry for making keys.
2. Classification According to Grade
Following are the different types of file tools according to the basis of the number of teeth
1. Rough File
In this type of file, teeth are of big size and less in number. It is used for cutting soft materials because its cutting is rough. Because of rough cutting, it cannot be used for hard metal.
2. Bastard File
3. Second-cut File
This is a file of medium grade. In the filler trade, this file is mostly used to bring the job in the proper size. As compared to the bastard file, filing done with this file makes the surface plain.
4. Smooth File
This file makes the surface quite plain, in addition to making a job of accurate size through filing.
5. Dead Smooth File
Its teeth are very close to each other and it rubs off the metal in very little quantity. It is used for bringing shinning on the job after finishing has been done.
3. Classification of Files On The Basis of Cut
Following are the different types of file tools according to the cut:
1. Single-cut File
This is the file has parallel lines of teeth running diagonally across its face in one direction only. The metal surface is rubbed in little quantity and thus the surface becomes smooth. Therefore it is used for hard metal and for finishing.
2. Double-cut File
This file has two rows of teeth crossing each other at an angle of 40° to 45° and the other row has angles of 70° to 80°.
Because of double teeth, this file cuts metal quickly but it cannot make the surface very smooth. That is why it is generally used for normal filing as shown in fig (B).
It is also called a coarse type file. In 30° to 35° and the other row is of 80° to 87° angles as shown in fig (C).
3. Curved-cut File
It is also known as the Vixen file. The curved-cut file is used for filing of the wide surfaces of soft metal like aluminum, zinc, copper, and brass. It has circular teeth as shown in fig.
4. Spiral-cut File
These types of teeth are cut in round or semi-round files. The shape of their teeth is like that of threads.
This is a file of special thick teeth. These teeth are of triangle shape and are in a bulging state. It is used for jobs of woods, plastic, fiber, hard rubber, and the job of horns and hoof of animals.
4. Classification According to Length
A file is measured according to its length. This length includes the whole file except its tang portion i.e. length from heel to tip is the measurement of the file. In fitter trade, files of 100 mm to 450 mm length are used.
