What Is File Tool?- Definition, Types, Uses And Features

What is File Tool?

A file is a tool used to remove fine amounts of material from a workpiece. It is common in woodworking, metalworking, and other similar trade and hobby tasks. Most are hand tools, made of a case-hardened steel bar of rectangular, square, triangular, or round cross-section, with one or more surfaces cut with sharp, generally parallel teeth.

A narrow, pointed tang is common at one end, to which a handle may be fitted. A rasp is a form of a file with distinct, individually cut teeth used for coarsely removing large amounts of material.

Files have also been developed with abrasive surfaces, such as natural or synthetic diamond grains or silicon carbide, allowing removal of material that would dull or resist steel files, such as ceramic.

File and Rasp Distinctions

When choosing between a file and a rasp it’s important to consider the material you’re working with and how fine of a finish you need.


  • Feature parallel, diagonal rows of teeth that form ridges across the surface. Each of the sides is either cut and has teeth or uncut and is smooth.
  • Single-cut files have one set of teeth and are used to provide a somewhat smoother finish or create a sharp edge on knives, shears or saws. Use light pressure when working.
  • Double-cut files feature a second set of teeth that cut in the opposite direction and are used for more aggressive filing, shaping or removing rust from metal and smoothing wood. Use heavier pressure when working.
  • Curved-cut files feature curved contours across the face of the file and are used for a variety of automotive applications, such as smoothing body panels. They can also be used for working with plaster and fiberglass.
  • Rasp-cut files feature a series of individual teeth and are used primarily on wood.


  • Feature individual teeth that are randomly placed to provide a faster, rougher cut.
  • Wood rasps have a very coarse surface and are used primarily for quick removal of stock.
  • Cabinet rasps are best suited for finer, more delicate work and can be used on wood of all types, leather or soft materials.
  • Patternmaker’s cabinet rasps provide a smoother finish.
  • Horse rasps are used for working on horseshoes.
file tool


File grades are often broken down into bastard cut, second cut, or smooth cut.

  • Bastard cut is the coarsest grade and is used to remove material quickly
  • Second cut can also be used for fast removal but it provides a slightly smoother finish. Second cut is also known as medium cut.
  • Smooth cut features a fine grade best used for finishing work and preparing surfaces for sanding.

Rasp grades include bastard, cabinet, and wood.

  • Unlike with files, a rasp bastard cut is the finest grade.
  • Cabinet cut is also known as medium cut.
  • Cabinet- and wood-grade rasps remove material quickly

Types of File Tools

A) Classification According to The Shape

The file tools are classified according to various types. One amongst this is the classification according to the shapes:

1. Flat File

A flat file is referred to as a file that is of a rectangular cross-section in shape. This instrument is designed in a slightly different way by tapering both the width and thickness of the file. Double cut teeth are cut on the face whereas the simple cut teeth are cut on the edges. These instruments are the ones that is used to reduce the flat surfaces by filing and finishing the workpiece.

2. Round File

As the name clearly tells, these are the types of files which is found to have a round section. This type of file is used for the purpose of rubbing or finishing the keyholes of a small diameter.

3. Half-Round File

Half-round files are the files that are found on the side and are curved on the other side. On the other hand, the double-cut dents are cut on it like a round file which is then tapered. These types of mechanical instruments are mainly used to repair the damaged hole and to also set them in order again.

4. Triangular File

The name clearly depicts the shape of such types of files. The files slots are found to have angles of 60 degrees. In order to complete the filing of the V slots job, the square and rectangular jobs ranging from 60°-90° angle are mostly done using this file. This type of file is also known as a three-square file.

5. Square File

These types of files are in the shape of a square and are found to be tapered. The slots of filing in a rectangular, square groove and key-way are done using these types of files.

6. Hand File

A hand file is quite similar to a flat-file which is mostly used for filing the internal right-angle side of a job. These types of hand files are also known as the safe edge file.

7. Knife-Edge File

Knife-edge files are used at places where there is a requirement for a sharp file. The shape of this type of mechanical instrument is like the edge of a knife. The thin edge is usually at an angle of 10°. These are also used for filing the small grooves and slots which are found to have an angle less than 60°. Knife-edge files are generally used in the lock industry for making the keys.

B) Classification According to Grade

The files are also classified according to the type of grade. Here are some of the most common types of files that are segregated according to the grade. Scroll down to know more about these types of files:

1. Rough File

These are the files that are found to have teeth of the bigger size and less in number. The round files are found to have their application in cutting the soft materials as its cutting is quite rough due to which, it cannot be used for the hard metals.

2. Second Cut File

A second cut file is referred to as a file that is found to have a medium grade. For the purpose of filling, this type of file is most commonly used in order to bring the job in a proper size. Comparing these types of files with the bastard file, filing is found to be done with this file in order to make the surface plain.

3. Smooth File

The smooth file is used at endless sites where the ultimate target is to get a smooth surface. These types of files are used to make the surface quite plain and other than this it is additionally used for making a job of accurate size by filing.

4. Dead Smooth File

The dead smooth file is designed in such a way in which its teeth are found to be very close to each other and rubs off the metal in very little quantity. These mechanical instruments are used for bringing shine to the job once the finishing has been done successfully.

C) Classification of Files on The Basis of Cut

The files are also classified according to the basis of cut. Here are some of the most common types of files that are segregated according to the type of cut. Scroll down to know more about these types of files:

1. Single Cut File

A single cut file is referred to as that mechanical tool that is found having parallel lines of teeth that run diagonally across its face and that too in one direction only. The metal surface is rubbed nicely in a little quantity and therefore the surface becomes smooth. Therefore, these are the devices that are used for the hard metals as well as for finishing.

2. Double-Cut File

The double-cut file is referred to as that file that has two rows of teeth crossing each other at a particular angle of 40°- 45° degrees and the other row having an angle of 70°- 80°. This is set in such a way due to the double teeth.

This file is responsible for cutting the metal quickly but on the other side, it cannot make the surface that smooth. These types of files are also referred to as a coarse type file having an angle of 30° to 35° in one row and 80° to 87° angle in the other row.

3. Curved Cut File

A curved cut file is also known as the Vixen file which is mostly used for filing of the wide surfaces of soft metal like aluminum, zinc, copper, and brass.

4. Spiral Cut File

This type of file has teeth, which are cut in round or semi-round files. The shape of the teeth in a spiral cut file is like that of threads.

5. Rasp Cut File

Rasp cut file is a type of file that has special thick teeth. These are the teeth that are of triangular shape and also are found to be in a bulging state. These are the files that are used for working in woods, plastic, fiber, hard rubber, and horns and hoofs of animals.

D) Other Types of Files Tool

Other than all the types of files which have been described above. There are various other most common types of files about which things are explained in detail. Scroll down to know more about these types of files:

  • Barrette files are tapered in width and thickness, coming to a rounded point at the end. Only the flat side is cut, and the other sides are all safe. For doing flat work.
  • Checkering files parallel in width and gently tapered in thickness. They have teeth cut in a precise grid pattern, and are used for making serrations and doing checkering work, as on gunstocks.
  • Crochet files are tapered in width and gradually tapered in thickness, with two flats and radiused edges, cut all around. Used in filing junctions between flat and curved surface, and slots with rounded edges.
  • Crossing files are half round on two sides with one side having a larger radius than the other. Tapered in width and thickness. For filing interior curved surfaces. The double radius makes possible filing at the junction of two curved surfaces or a straight and curved surface.
  • Dreadnought (curved teeth) and millenicut (straight teeth) files both have heavily undercut, sharp but coarse teeth. Both can be used for rapidly removing large quantities of material from thick aluminum alloy, copper or brass. Today, the millenicut and dreadnought have found a new use in removing plastic filler materials such as two-part epoxies or styrene’s such as those commonly used in automobile body repairs.
  • Equaling files are parallel in width and thickness. Used for filing slots and corners.
  • Farrier Rasp files are tanged rasps used mainly by farriers and blacksmiths. They are flat with a rasp on one side and double cut on the reverse.
  • Fret files are square or rectangular with three flat sides and one side having a concave groove. They are used by luthiers to file a rounded “crown” on the frets of guitars and other fretted instruments. The flat faces are used to dress the ends of the frets, removing the sharp edges left after the frets are trimmed to length.
  • Half round ring files taper in width and thickness, coming to a point, and are narrower than a standard half round. Used for filing inside of rings.
  • Joint round edge files are parallel in width and thickness, with rounded edges. The flats are safe (no teeth) and cut on the rounded edges only. Used for making joints and hinges.
  • Knife files are tapered in width and thickness, but the knife edge has the same thickness the whole length, with the knife edge having an arc to it. Used for slotting or wedging operations.
  • Nut files are fine, precise files in sets of graduated thickness, used by luthiers for dressing the slots at the end of the neck which support the strings of guitars, violins etc., in the correct position.
  • Pillar files are parallel in width and tapered in thickness for perfectly flat filing. Double cut top and bottom with both sides safe, these are long, narrow files for precision work.
  • Pippin files are tapered in width and thickness, generally of a teardrop cross section and having the edge of a knife file. Used for filing the junction of two curved surfaces and making V-shaped slots.
  • Plane maker’s float Floats are straight, single-cut files which taper used for cutting, flattening and smoothing wood, particularly in making wooden hand planes.
  • Round parallel files are similar to round files, except that they do not taper. Shaped like a toothed cylinder.
  • Saw sharpening files are usually single cut to deliver a smooth finish. They are suited to sharpening saw blades and dressing tool edges, especially where a finer, sharper edge or smoother surface finish is desired. The Chainsaw file is one example, used primarily for sharpening chainsaws. These appear to have a round cross-section, but are actually shaped to fit snugly against the cutting edge of a chainsaw’s teeth.
  • Slitting files are parallel in width with a diamond-shaped cross section. Thinner than knife files and use for filing slots.
  • Warding files are parallel in thickness, tapered in width, and thin. Like a hand or flat file that comes to a point on the end. Used for flat work and slotting.

Usage and Care

It’s important to choose the right combination of shape, size, and grade for the project you’re working on. Also, proper care and technique are key to safe and effective use.

  • When using tool push outwards across the surface and adjust pressure according to type of material you’re working with.
  • Lift the tool at the end of the stroke and bring it back to the starting position before allowing it to touch the surface again.
  • When files become clogged clean them with a wire brush or file card. Rubbing chalk on the surface of the tool can help prevent clogging.
  • Always work in a well-ventilated area and use respiratory protection when necessary.
  • Keep files in protective sleeves or slotted racks when not in use to prevent them from scraping against each other.


  • Handles. Ergonomic handles feature rubberized grips that provide greater comfort when using tools. Universal handles feature inserts that allow it to be used with different shapes.
  • 4-in-1 Tool. A multi-faceted tool used for many different tasks. Some files are designed with both round and flat surfaces and others are a file and rasp in one tool.
  • File Card. Used to get in between the teeth of files and rasps to clean out sawdust, metal shavings and other debris.
  • Diamond File. Features ground diamond particles that make them well suited to industrial applications. Best used when working on fiberglass, epoxy and other hard surfaces. Smaller diamond files work well on glass, ceramic and various metals.