Types of File Tools

File tools are a crucial part of woodworking and metalworking projects. They are the form of hand tools that are also used for trade and hobby tasks. They are usually made up of a case hardened steel bar of various shapes like rectangular, square, triangular, or round cross-section. It has parallel teeth and narrow pointed tang at ends. It is made up of abrasive surfaces such as natural or synthetic diamond grains or silicon carbide. This allows the proper removal of material. These file tools come in a wide variety based on materials, sizes, shapes, cuts, and tooth configuration. These file tools are mainly used for giving final finishing to a job, smooths the surface, resizing of the object, sharpening the edges of cutting tools, etc. Below are some of the types of file tools that are discussed.

Different types of file tools:

Various common types of files available can perform the primary filing task in the project. Let us have brief learning on each of these types.

1. Flat file – It is the single cut hand that can be used as a substitute to sharpen tools with blades, used for smooth finishing over the surfaces, or for deburring. It is used to put a bevel on the edge of the metal piece. It is also used to round corners and create a convex surface. It has a rectangular cross-section. The edges along the width of this file are parallel up to 2/3rd of the length and tapering design towards the point. The faces are double cut and edges single cut. They are mostly used for general purpose work. 

2. Hand file – They are blunt and have a slight taper in thickness. It has one safe edge that suits it for filling in corners as well. They are similar to flat files. But they are flat on the top and bottom side. The sides of the file are parallel along the length of the blade and don’t have a tapering design. They come in various lengths, styles and cuts. They too are used for general work.

3. Square file – It is a metal tool with a rough surface. It is used to remove small amounts of wood or metal from a work-piece. It is called a single cut when only one set of such ridges has been cut, and double-cut when two sets of ridges have been cut forming diamond-shaped teeth. As the name suggests, it has a square in its cross-section. The design is gradually tapered and cut on all four sides. It is used for different tasks like filing square holes, internal square corners, rectangular opening, key-ways and splines.

4. Round file – They are also known as machinist’s files. It is used for creating semicircular grooves, finishing, deburring concave surfaces. It is used in jewellery making to create detailed patterns in ornaments. It has another name called rat’s tail. It is circular in its cross-section and equal diameter over the length. It is used for smoothing inside holes and circular grooves, for sharpening certain kinds of saws, and filing profiles with fillets. 

5. Half-round file – They are two-sided files having a rounded face on one side and a flat face on the opposite side. It is ideal for rounding out holes and is used on a concave, convex or flat surface. It is tapering slightly or maintaining an even thickness, width or both over their length. It is in the shape of a segment of the circle. It is used for filing internal curved surfaces.

6. Knife-edge file – They are tapered in width and thickness, although they have the same thickness from shoulder to point. It is used to file in a slot or wedge-shaped opening. The curved style design allows the user to do filing even in the restricted areas. Double cut on both sides, top edge is safe while the knife edge is single cut. It has the same thickness over the whole length with a knife-edge having an arc to it. It is used for slotting or welding operations. It has a cross-section of sharp triangles. It is used for filing narrow grooves and angles above 10 degrees. 

7. Triangular file – It is a file that has a triangular cross-section. They may taper gradually to a point in case of smaller files. The sides can either be equal in cross-section or have two long and one short surface. It has 3 tapered sides which are used to file internal surfaces of objects with acute angles. They are most commonly used by carpenters to sharpen the teeth of hand saws or to smooth various surface areas. Also, they are used for filling corners and angles, which are more than 60 degrees. They are made in bastard, second cut, and smooth grades. 

Needle files – They are small files used to finish and shape the metal. It has a smooth edge on one side to perform without creating a mark on metal while working in tight spaces. It comes in various shapes like round, half-round, square, triangle, flat and Barrett. They are mainly used for delicate and light kinds of work. 

There are some of the special files available like – 

1. Riffler file – They are double-ended tools that are designed to file in tight areas and irregularly shaped spaces as well. They come from small to medium size in an assortment of cross-sectional shapes and profiles. They come with standard cuts of teeth. They are usually used as an intermediate step in die making where surface finishing of a die is to be made. E.g. in plastic injection molding or die casting. They are also used for die sinking, engraving and silversmith’s projects. 

2. Mill saw file – It is a multi-purpose file that is commonly used for sharpening blades. They are also used even out to saw teeth at the beginning of the sharpening process. They are hand files with safe edges. They are always single cut and are used for primary finishing work and draw filing. Also, they are used to sharpen mill and circular saw blades, knives and lawn mower blades. They have a rectangular cross-section with an even thickness throughout their length. They may be either parallel-sided or taper slightly in width from heel to end. 

3. Crossing file – It is similar to a half round file but convex on both faces. One side has a larger radius than the other. They are tapering in width and thickness. The double radius makes it possible to file at the junction of 2 curved surfaces or straight and curved surfaces. Each side of the file has different curves. It is also known as fish back file.

4. Barrette file – They are a machinist’s file with only one cut on one face. Only one part of the file can cut a work-piece leading to a great degree of security from any error. They are tapered in width and thickness coming to a rounded part in the end. It has a flat, triangular face with teeth on the wide face. It is used for finishing sharp corners. 

5. Machine files – As the name suggests, it is used for filing the machines. It looks like a scroll saw with a vertically reciprocating file mounted in the middle of the table. It has a cone point that allows mounting the file in the centre point. It is suggested to secure the flat mounting files with a set screw. They have a double cut with a hole for fixing the holder of the filing machine. They are suitable for filing both inner and outer surfaces. They come in different lengths and shapes. They are ideal for die-sinking and other tool room work. 

6. Dental files – They are specially used for root canal therapies. These round files ranging from diameter 0.6 – 0.8 millimetres are used to smooth the narrow canals of tooth interiors. It thus helps in facilitating disinfection of the internal surface. They are made up of stainless steel or nickel-titanium and come in various styles. The mechanized type is also known as rotary files. They are attached to the head of a specific oscillating or rotating drill. 


Hope the above piece of article is helpful for you in deciding which file to select for your project. It will not only save your time in choosing the tool but also assure you in getting effective results. Do let us know in the comment section below if we have missed any type of file tool that you would like us to add in our list.

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