File type classification

A large variety of shapes and sizes of notches files led to the fact that a non-specialist to understand the purpose for which to use this or that tool, it became very difficult. To improve the situation, a classification of files was developed. This classification, gradually changing and supplementing with new types of tools, is still in effect.

File device diagram

File device diagram.

The appearance of the file

Even in the age of space technology, most works on metal or wood cannot do without a file. Despite the very respectable age of the tool, its purpose remains the same - by the method of layer-by-layer grinding of the surface of the part to form the required size and shape for it.

Domestic files are made from two groups of high-quality tool steels - alloyed chromium steel grades SHKh15 and 13X or unalloyed improved steel grades U10A - U13A.

The file belongs to the cutting tools. In appearance, the file is a bar of a special steel grade, the surface of which is cut according to a special pattern. Most of the files have a rectangular, triangular or circular section of the bar, although other options are possible.

A wooden or plastic handle is fixed on the tapered cone of the file. It serves exclusively for the convenience of working with the tool, and has no influence on the quality of the tool itself. Therefore, throwing a tool with a flying handle is stupid, it can easily be replaced with another.

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Notch numbering

Notch numbering table

Notch numbering table.

The use of files is largely determined by the type of incision made and the configuration of its teeth. For the application of teeth can be used the method of incision, milling, cutting, pulling and turning. The most common files today are those with teeth notched on special machines.

Overwhelmingly, the notch of files can be single or double. A single notch allows you to remove sawdust equal to the size of the teeth. It is very difficult to work with such a tool, therefore, it is mainly used for processing soft metals, plastics and wood.

Double (cross) notch is obtained by a combination of the main, deeper, and auxiliary, smaller, made at an angle to the main. Intersecting incisions grind chips that form during operation. Use such a notch for processing of solid metals and alloys.

The size of the file teeth depends on the size of the notches per 1 cm of the length of the bar - the smaller the notches, the larger the tooth. By the size of the teeth, the files are from 0 to 5 numbers (there are 6 of them altogether), and in the shape of the incisions made there are single, cross (double) and rasp notches.

The largest notch teeth denote # 0 and # 1. These files are used when you need to quickly remove a sufficiently large layer of material (0.05 - 0.10 mm). The main drawback of tools with such a notch is the low precision of machining parts - it does not exceed 0.1 - 0.2 mm.

File Work Pattern

The scheme of the file.

The tool with teeth No. 2 and No. 3 is used when it is necessary to remove a layer of material in the range of 0.02-0.06 mm. The accuracy of their work is 0.02 - 0.05 mm.

For a fine finish of parts, a tool is used with an accuracy of processing of 0.01–0.005 mm, with notches No. 4 and No. 5 teeth (they are called velvet).

They can remove the layer of material not more than 0.01 - 0.03 mm.

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File types

According to their purpose, files are divided into several large groups:

  • general purpose;
  • special purpose;
  • machine;
  • rasps;
  • files

General purpose files are used for general plumbing work. The notch for tools of this group is performed in the way of incision, equipping them with a double (cross) notch. They can be of different lengths (from 100 to 450 mm), have a different bar shape and almost all notches.

Fitter files for special jobs are mainly used in industrial conditions, since their purpose is to eliminate large allowances when fitting grooves and different curvature of surfaces; they can be used to process non-ferrous metals. Depending on the work performed, they can be flat, lumber, groove, double-ended and other forms.

The most numerous group of needle files - there are as many as 11 types: flat, round, semicircular, square, triangular, oval, hacksaw, etc. Needles can be distinguished by a small bar length (40, 60, or 80 mm) and a notch of the highest, 5th grade.

Types of files in form

Types of files in form.

The files are mostly equipped with a double notch, although the edges of the flat files can be single. Used primarily for the processing of small parts or bottlenecks, where the usual plumbing tools can not be reached.

Rasps are divided into three types: shoe, ungulates and general purpose. Their distinguishing feature is a large length (from 250 to 350 mm) and large notches on the teeth - it is not less than №1 in rasps. Usually rasps are round or semi-circular, as well as flat with blunt or sharp noses.

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The use of files of various shapes

The shape of the bar is very important, it can immediately determine the scope of the tool. Files according to the method of use are:

  • flat or flat sharp-nosed, intended for the treatment of internal or external flat surfaces;
  • square, designed for sawing rectangular, square and polygonal holes;
  • triangular, intended for processing in grooves, holes and grooves, as well as on the outer side of parts sharp (from 60 º) corners;
  • semicircular, designed to handle large holes and concave surfaces of significant radius of curvature;
  • round, designed for processing small round or oval holes or a small radius of concave surfaces;
  • rhombic, designed to work with toothed parts;
  • hacksaw, intended for selection of narrow grooves, grooves, for processing of internal corners, and also the planes in openings of a square, diamond-shaped or rectangular shape.
Types of notches

Types of notches.

Such a variety of tools of one type can confuse even a specialist. If you do not do professionally work on metal or wood, but use a file from time to time, then it is not at all necessary to purchase tools of all sizes and shapes for your home workshop. Most of the operations can be performed with only three types of files - flat, triangular and round, but it is necessary that these types be of all three main groups: metalwork general-purpose files, files and rasps. When they are in your workshop, you can do any task.

In direct relation to the type of material, its heat treatment and the quality of performance of the notches is the tool life.

Choosing a file in the hardware store, be sure to pay close attention to its appearance.

Professionals are advised to choose a tool that has a uniform steel surface color, a clearly visible notch without any signs of defects. If on the surface you find stains, traces of rust or oil stains, then such a tool is definitely better not to take, for a long time you will not use it anyway.

Make no mistake in choosing! Good luck!

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