A wide variety of shapes and sizes of file notches led to the fact that it became very difficult for a non-specialist to understand for what purposes it is necessary to use this or that tool. To improve the situation, a file classification has been developed. This classification, gradually changing and replenished with new types of tools, is still valid today.

File Appearance

Even in the age of space technology, most metal or wood work cannot do without a file. Despite the very venerable age of the tool, its purpose remains the same - to form the desired size and shape by layer-by-layer grinding of the surface of the part.

Domestic files are made from two groups of high-quality tool steels - alloyed chromium steel of grades ШХ15 and 13Х or unalloyed improved steel of grades У10А - У13А.

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

A wooden or plastic handle is attached to the tapered tapered shank of the file. It serves solely for the convenience of working with the tool, and has no effect on the quality of the tool itself. Therefore, throwing away a tool with a flying handle is stupid, it can easily be replaced with another.

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Notch Numbering

The use of files is largely determined by the type of notch applied and the configuration of its teeth. For applying teeth, the method of notching, milling, cutting, pulling and turning can be used. The most common files today are teeth incised on special machines.

The vast majority of file cuts are single or double. A single notch allows you to remove sawdust equal to the size of the teeth. Working with such a tool is very difficult, therefore, it is mainly used for processing soft metals, plastics and wood.

A double (cross) notch is obtained by combining the main, deeper, and auxiliary, shallow, made at an angle to the main. Intersecting notches grind the chips formed during operation. Use such a notch for processing hard metals and alloys.

The size of the teeth of the file depends on the size of the notches per 1 cm of the length of the bar - the smaller the notches, the larger the tooth. Files can be from 0 to 5 numbers in size of teeth (there are 6 in total), and according to the shape of the notches, a single, cross (double) and rasp notches can be distinguished.

The largest teeth of the notch are designated No. 0 and No. 1. Such files are used when it is necessary to quickly remove a sufficiently large layer of material (0.05 - 0.10 mm). The main disadvantage of tools with such a notch is the low accuracy of machining parts - it does not exceed 0.1 - 0.2 mm.

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

For the finishing of parts use a tool with a machining accuracy of 0.01 - 0.005 mm, with teeth of the notches No. 4 and No. 5 (they are popularly called velvet).

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

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File Types

Files are divided into several large groups according to their purpose:

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

General purpose files are used for general metalwork. The notch for tools of this group is performed by the notching method, equipping them with a double (cross) notch. They can be of various lengths (from 100 to 450 mm), have a different bar shape and almost all the notch numbers.

Locksmiths for special work are mainly used in industrial conditions, since their purpose is to eliminate large allowances when fitting grooves and different curvatures of surfaces, they can be used for processing non-ferrous metals. Depending on the work performed, they can be flat, squared, grooved, double-end and other shapes.

The most numerous group of files - there are as many as 11 types: flat, round, semicircular, square, trihedral, oval, hacksaw, etc. You can distinguish files by the short length of the bar (40, 60 or 80 mm) and a notch of the highest class 5.

Most files are equipped with a double notch, although the edges of flat files can have a single one. It is used mainly for processing small parts or bottlenecks where conventional metalwork tools cannot be reached.

Rasps are divided into three types: boot, ungulate and general purpose. Their distinguishing feature is a large length (from 250 to 350 mm) and large teeth of the notch - it is not less than No. 1 for raspings. Usually, rasps are round or semicircular, as well as flat with blunt or sharp noses.

Among domestic plumbing masters, there is an opinion that for the manufacture of any metal part it is enough to give it an approximate outline - the rest can be finalized with a file. Together with a hammer and pliers, this hand tool is one of the three most popular helpers of any "homemade".

With their help, you can perform a variety of work on metal and other materials:

• Removing contaminants, corrosion and various coatings;
• Grinding surfaces from rough to finish
• Giving the necessary shape to the product;
• Deburring, flashing;
• Cleaning contacts, preparation for painting;
• Sharpening cutting and sawing tools.

The principle of operation is very simple. With the help of notches on the surface (teeth), a small layer of the processed material is removed. Depth of processing is regulated by pressing force, the number of movements and speed.

The industry produces countless files and files designed for a wide variety of work and materials, we will help you understand the types of tools.

Types of files and their purpose

As with any other instrument, there are differences in performance, material and application.

Tooth size

The most common classification of files is by the density of the cutting of the teeth.

No. 1 - a large notch from 5 to 13 teeth per 1 cm.

The tool is designed for rough, rough machining. With sufficient softness of the material - you can confidently squeeze a thick layer in several passes. Hard workpieces are difficult to work with. The series is called "bastard files."

No. 2 - an average notch from 14 to 25 teeth per 1 cm.

The most common and most versatile type of tool. In classical processing - this file is used after dracheva, to smooth the surface. In reality - most often work is performed only by this number.

You can grind any material. Soft metal or wood quickly clogs the pores between the notch; cleaning with a wire brush is required. The series is called "personal files."

Each sawing method corresponds to a specific geometry of the teeth of the file. The tooth geometry of the notched files is characterized by the following angles (Fig. 38 b): cutting angle δα \u003d 106 °, rear angle α \u003d 36 °, point angle β \u003d 70 °, rake angle ƴ negative to 12-15 °. The rake angle according to GOST 1465-59 is set to -12 ° for files with a notch No. 0, 1 and 2 and up to -15 ° for files with a notch No. 3, 4 and 5.

The geometry of the teeth of files made by milling and grinding is characterized by the following angles: cutting δ \u003d 80-88 °, rear α \u003d 20-25 °, sharpening β \u003d 60-63 °, front γ from + 2 to -10 °. By purpose, files are divided into two groups: metalwork general purpose, designed to perform various metalwork on metal; and special, designed to perform various works on metal and non-metallic materials. Special files are divided into manual and machine.

Files are made with a notch of the following types: simple, or single (Fig. 38, c); with cross, or double (Fig. 38, d); with a point, or rasp (Fig. 38, e); with an arc (Fig. 38, f). Each type of notch has its own advantages and is used for files of a specific purpose.

A simple or single notch is used in the manufacture of certain types of special files (for example, for sharpening saws on wood). Files with a simple notch are advisable to use in all cases when it is required to remove a small layer of metal from a narrow work surface.

Cross, or double, notch is used in the manufacture of general-purpose lock files. In these files, the main notch is made at an angle λ \u003d 25 °, and the auxiliary notch at an angle ω \u003d 45 ° (Fig. 38, g).

Such notch angles provide high performance.

A point or rasp notch is used in the manufacture of rasp files. Rasps with a dotted notch have large teeth and roomy grooves, which contributes to better chip separation when sawing soft metals, rubber, leather, plastics, etc.

Locksmith files differ in two main ways: in cross-sectional shape and in the number of notches per centimeter of file length.

Locksmith files (GOST 1465-59) are made in eight cross-sectional shapes: flat (type A), flat pointed (type B), square (type C), trihedral (type G), round (type D), semicircular (type E), rhombic (type G), hacksaw (type K).

Types of file notches

According to the number of notches, the metalwork files are divided into six numbers: 0, 1, 2, 3, 4, 5. The notch number is an indicator of the operational purpose of the size range of files according to the pitch of the main notch.

Files with a notch No. 0 and 1, the so-called drastic, have the largest teeth and are used to file parts with an accuracy of 0.2-0.5 mm that have a machining allowance of 0.5 to 1 mm.

Files with notch No. 2, the so-called personal files, are used for finishing filing parts with an accuracy of 0.02-0.15 mm, while the allowance for processing is from 0.1 to 0.3 mm.

Files with notches No. 3, 4, 5, the so-called velvet, are used for the final finishing of parts with an accuracy of 0.01 to 0.005 mm, while the allowance for processing ranges from 0.025 to 0.05 mm.

Files are made of tool carbon steel U13 or U13A and hardened to a hardness of at least HRC 54-58.

Rasps differ from the metalwork files by a notch, their teeth are large short in the form of pyramids. Due to the large size of the teeth and the spacious grooves behind each tooth, the rasps are suitable for sawing soft metals. The rasp teeth are arranged in rows perpendicular to its axis. So that when filing does not turn out grooves, the rows are offset relative to each other by half a step between the teeth.

In the mednitsa and tin cases, they use general-purpose rasps (GOST 6876-54) for filing parts of soft metals (aluminum, duralumin, etc.). General purpose rasps are made of four types: flat blunt, flat pointed, round and semicircular. All four types of rasps are made in 250 and 350 mm lengths.

For the manufacture of rasps, tool carbon steel is used mainly of the grades U7A, U10A, hardened to a hardness of HRC 35-40.

The smallest files, the so-called files, are designed to perform very fine and precise work. They vary in cross-sectional shape and in the number of notches per centimeter of file length.

Needle files (GOST 1513-67) are made according to the cross-sectional shape of eleven types: flat blunt, flat pointed, square, trihedral, trihedral unilateral, round, semicircular, oval, rhombic, hacksaw and groove.

By the number of notches, the files are divided into six numbers: 1, 2, 3, 4, 5, 6.

Flat files are blunt, flat, pointed, square, trihedral, round, semicircular, rhombic, grooves are made in two sizes: the length of the working part is 60 and 80 mm and the length of the shank is 60 and 80 mm, respectively.

Three-sided, oval files are made of three sizes: along the length of the working part 40, 60, 80 mm and the length of the shank, respectively, 80, 60, 80 mm.

Hacksaw files are made in three sizes: along the length of the working part 60, 80, 40 mm and the length of the shank, respectively 60, 80, 80 mm.

Files are made of tool carbon steel U12 or U12A and hardened to a hardness of HRC 54-60.

The file has a wooden handle with a clamping ring, which protects it from cracks when mounted on the shank of the file. The handle must fit snugly onto the file shank, for which a hole is drilled in it with a diameter corresponding to the size of the middle part of the shank and a depth equal to the length of the shank. Then, with a heated red-shank of an old file of the same size, a hole is burned out exactly in the shape of the shank by 2 / 3-3 / 4 of its length. When putting the handles on the shank, one should not hit the file with a hammer, since its cutting part may break. When put on correctly, the handle is hit on a bench while it sits firmly on the shank. When pushing the handle onto the shank of the file, make sure that it is planted without distortion.

Handles are made of wood (birch, beech) or pressed paper. Wooden handles are used more often, as they are more practical. The length of the handle should be one and a half times longer than the file shank.

Handles for general-purpose files are made with a length of 90, 100, 110, 120, 130, 140 mm, with a diameter at the end of it, respectively, 12, 16, 20, 23, 25, 28 mm. The size of the handle is selected according to the size of the file.

Grinding metal is not always done with a power tool. Sometimes files are used for such work, the main thing is to choose them correctly. This tool is of two types - for metal and wood. Files designed for metal are harder than counterparts used for wood. This is because the surface of the metal is processed much more difficult than wood.

Such tools are made of very hard steel, and differ from each other in different shapes and sizes of notches. This diversity has made it quite difficult for the average man to figure out for what purpose is this or that tool. To improve the situation, their classification was developed, which is valid at present.

File Features

Despite the fact that modern technologies have reached great heights, a file is still used for metal work. Its purpose is using surface grinding  any part to give it the necessary shape and size.

The file is a cutting tool. Its appearance is a bar, for the manufacture of which special grade steel is used. Its surface is excised according to a special pattern.

On tapered tapered shank there is a plastic or wooden handle. It is provided only to make it convenient for working with the tool. If suddenly it flies, then it can be easily replaced with another.

Types of notches

To choose the right file, you must determine the type of notch applied and the configuration of its teeth. For applying teeth, the method is used:

• milling;
• pulling;
• insects;
• slicing;
• turning.

  Files with teeth notched on special machines are considered to be the most popular today. Most often, notches are single or double. Single notch removes sawdustwhich are equal in size to the teeth. It is very difficult to work with such a file, therefore they mainly process soft metals, wood and plastic.

A double notch is formed as a result of a combination of the main and auxiliary, which is performed at an angle to the main. Such notches grind the chips that are formed during operation. They process alloys and hard metals with this file.

The size of the teeth depends on the size of the notches per 1 cm of the length of the bar - the smaller they are, the larger the tooth will be. Depending on tooth size the instrument is from 0 to 5 numbers. The largest teeth are designated by numbers 0 and 1, they allow you to quickly remove a fairly large layer of material (0.05 - 0.10 mm). The main disadvantage of a tool having such a notch is the low accuracy of the machined parts, which is 0.1 - 0.2 mm.

A tool with teeth numbered 2 and 3 is used when it is necessary to remove a layer of material from 0.02 - 0.06 mm. File with notch teethhaving numbers 4 and 5, is used for the finishing of parts. The processing accuracy is 0.01 - 0.005 mm. Such teeth remove the layer of material 0.01 - 0.03 mm, not more.

File Types

The instrument in its intended purpose is:

• general purpose;
• needle files
• special purpose;
• rasped.

  General purpose files are mainly used for locksmithing. They have a double notch with notched teeth. The notches have different lengths (from 100 to 450 mm), and the teeth are almost all numbers.

A special purpose file is most often used in industrial conditions, as helps eliminate large stocks  when fitting grooves and different curvatures of the surfaces. Depending on what kind of work will be carried out, special-purpose files are divided into flat, groove, double-end and others.

The largest group is needle files, there are 11 types: round, square, oval, flat, semicircular, trihedral, hacksaw, etc. They are characterized by a short bar length and notches of grade 5. Most often they are equipped with a double notch. Use this file to process small parts or places where ordinary metalwork tools cannot reach.

File  - a cutting tool for processing materials by the method of layer-by-layer cutting (filing). It is a strip (web) of hardened high-carbon (carbon 1.1-1.25%) steel of various cross sections, on the working surfaces of which a “notch” is created - cutting elements (sharp teeth). A handle is attached to the tapered shank of the file.

Files require greater hardness, so after quenching they are not subject to tempering.

Files come in various shapes and sizes, and besides, they differ in the nature of the notch.

Files can vary greatly in size, starting with the smallest, 50 mm long, and ending with the largest, 450-500 mm long. When determining the length of a file, only the notched part thereof is measured.

File length - its working part excluding the shank. Size range in (mm): 100, 125, 150, 200, 250, 300, 350,400.

File Categories

Hand files fall into four main categories:

• Metalwork files;
• Needle files;
• Sharpening Files;
• Rough files (rasps).

Needle files  - These are small files, used for patterns, engraving, jewelry, as well as for stripping in hard to reach places (holes, corners, short sections of the profile, etc.).

Rasps  Designed for processing soft metals (lead, tin, copper, etc.) and non-metallic materials (leather, rubber, wood, plastics), when ordinary files are unsuitable.

File Shapes

• Flat files  (pointed and blunt; with oval ribs) - filing easily accessible flat and convex surfaces, as well as for sawing slots and grooves; filing fillets and various other roundings and flat slots with oval transitions;
• Square Files  - sawing square and rectangular holes, narrow flat surfaces, not available for use with a wide flat file;
• Round files  - a round file is used for sawing round or oval holes and concave surfaces that are not available for a semicircular file;
• Triangular (trihedral) files  - filing of internal corners and trihedral openings, planes in places inaccessible to a flat file;
• Semicircular files  (pointed and blunt) - flat side filing a plane, semicircular side - filing concave surfaces (semicircular grooves);
• Diamond files;
• Files of a special form;

The figure below illustrates how to use files of various shapes.

File cut

Types of notches:

• Single notch  - applied at an angle of 70 ° to the longitudinal axis of the file, sometimes at 45 °. It removes wide chips from the processed material and is intended to obtain a surface with a slight roughness;
• Double (cross) notch - is a combination of a single notch and a less deep auxiliary, made at an angle to the single. The intersection points of these notches break the resulting chips during filing. Such a notch is basic for locksmith files;
• Double ("oberg")  - with a rarer (2-3 times) auxiliary notch. It occupies an intermediate position between single and double notches in terms of efficiency and cleanliness of surface treatment;
• Rasp (dot) notch  - used for processing very soft metals and non-metallic materials - leather, rubber, etc. Rasp (dot) notch is obtained by pressing metal with special chisels;
• Arc notch  - files with an arc notch are used in the processing of soft metals. Arc notch is obtained by milling; it has large cavities between the teeth and an arcuate shape, providing high performance and high quality machined surfaces.

Depending on the material being processed, one or another form of file cut is used. When processing soft metals, which have a relatively small resistance to cutting, files with a large single-row notch are used. For processing aluminum or copper, special-purpose files are used for processing non-ferrous alloys, which, in contrast to general-purpose metalwork files, have other, more rational for this particular alloy, notch tilt angles and a deeper and sharper notch, which ensures high performance and durability of files. For processing more or less hard metals (steel and cast iron), with high resistance to cutting, files with a double, cross notch are used. Sawing them with wide teeth would be very difficult.

The size of the notch is the number of teeth per 1 cm of the length of the file of the file.

According to the number of notches (teeth) per 1 cm of length, files are divided into six classes, and notches are numbered 0, 1, 2, 3, 4, and 5.

• Bastard files (notch 0 and 1)  - the coarsest notch, has a small number of teeth per 1 cm;
• Personal files (notches 2 and 3)  - average notch, the number of teeth is 1 cm more than the previous one;
• Velvet files (notches 4 and 5)  - a small notch, the largest number of teeth per 1 cm.

Basically, the coarser the notch, the higher the material removal rate.

Long files have a larger notch than short ones. In all cases when you need to remove a large layer of material, use files with a large notch. The surface is rough, scratched and inaccurate. If you want to get a smoother and more accurate surface, then use files with a finer notch. Therefore, when you need to remove a large layer of metal and get a smooth surface, then first filed with a file with a large notch, and then trimmed with a file with a small notch.

The same number of teeth per 1 cm, but on files of different lengths will refer to different sizes of the notch. For example: 20 teeth per 1 cm with a file length of 200 mm - a personal notch, the same number of teeth per 1 cm on a file of 300 mm - velvet.

How to choose a file?

• The file should have the correct shape, a good notch, be well hardened and not have cracks.
• Files are inspected from the outside and checked for sound. When you hit an anvil or another metal object, a good file should make a clear sound. A rattling sound indicates cracks in the file.
• The file should not be bent, which can happen during hardening. Its teeth should be sharp, with a bias towards the nose of the file, and the notch is even, without gaps. The surface of the file should be clean, without rust spots.
• The file should have a uniform gray color of the entire surface, without streaks (indicating violation of the heat treatment modes), traces of rust, oil and other contaminants.
• The file must have a handle tightly attached to the shank (without visible defects), if the file is equipped with it.