How to chop the thread with a tank or a rash. We study a specialized tool. How to cut into internal threads - Types of testers, technology, internal thread cutting tips

Do you like to improve the home arrangement at home, not attracting various masters for this? Independent installation Or repair not only allows you to save money on the challenge of specialists, but also greatly improves self-esteem, because right?

In the process of installing communications, it is often necessary to prepare threads on pipes. You have to seek ways to not spoil the product.

We will tell how to cut the thread with different toolsWhich method is preferable to use in a particular situation. The article discusses the methods available to implement an unqualified performer. Illuminated Features of cutting different types Threads and equipment used at the same time.

The stated material is provided with visual photographic materials with the image of the tool to perform work. A video with recommendations will help to deal in detail with all the subtleties of this process.

The term "tubular" has a privileged position in the sphere of sanitary activities. It is classified this term with a loan to a group of standards that determine the criteria for compounds. various elements Plumbing structures.

Pipe threads widely used in systems of water supply and sewage networks, so the practice of cutting, manually or automatically, is the activity of frequently applicable

For example, the size of the pipe thread is indicated numerical meaningindicating the standard of pipe diameter of the pipe, but not the physical cutting diameter.

In practice, tube threads are used:

cylindrical ( G / BSPP.),
conical ( R / BSPT.),
round for shut-off plumbing fittings ( Kr),
inch cylindrical (American standard NPSM.),
inch Cone (American Standard NPT.).

Slicer, the main working part of which is a household, it is recommended to take the conditional separation of the pipe thread into two main types:

cylindrical ( G.),
conical ( R.).

It is with these two species that accounted for most often to face a homely watchman serving household plumbing equipmentperforming gasket or heating.

Cutting pipes are made in the following cases:

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Main ways of cutting

Cutting on pipes by carving can be one of two ways:

automatic - on machines, power tools;
manually - With the help of a hand tool.

For the conditions of life, of course, more relevant is manual technology. Cutting the threads on water and other pipes manually is often made with a dice.

The dice is solid for pipe threads made of strong alloy steel, are produced with a diameter of the housing up to 65 mm. Under the metric threads are produced dies with a body diameter up to 120 mm. On the housing of metric products there is a symbol "M"

The cry is a simple device for cutting the thread on pipes at home. The same tool is successfully used on industrial machines.

The device looks like a disk, on the internal diameter of which several axial holes are drilled. The edges of these holes form several incisors (usually 8-10). Alloy steel or other solid alloys is served material for the dice.

There are several types of such devices:

whole;
spring-loaded (cut);
clupp (sliding).

In the form of execution, the dice is produced in the form of a circle, square, hexagon, prism. Most often there are disk (round) tools. They are used under the cutting of the thread on the plumbing pipes to a diameter of 36 mm.

For the convenience of working with dies apply:

simple grooves with screws-locks - a hand tool;
threaded cartridges On lathes.

Cutting thread (metric, conical) best quality On pipes in manual mode or on machines, one-piece dies are given.

However, this type of tool due to rigidity own design Has own negative sides. The cutters quickly wear out.

A spring-loaded thread cutting tool is distinguished by the presence of a cut in the area of \u200b\u200bone of the axial holes. The presence of a cut reduces the load on the incisors, but it decreases and the degree of rigidity required to achieve high drawing quality indicators

The spring-loaded (cut) dies have a design less rigid, which makes it possible to cut the thread on the pipes and at the same time changing the thread diameter in the range of 0.1-0.3 mm.

Such devices are distinguished by increased wear resistance of incisors, but do not provide high precision and purity cutting threads.

Sliding dies consist of two operating parts. They are designed to be installed in the Fastener Module - Klupp.

Fastening in the club is carried out by a mechanism consisting of a crush and an adjusting screw. The screw adjusts the size of the diameter under the cutting of the thread. Usually, the Klupp is equipped with a set of dies into several different diameters.

Method # 1 - Production of pipe threads with dies

The process of creating a thread on a pipe with a piercing or clupp implies execution by the mechanic of some preliminary action:

The surface of the pipe in the cutting area must be carefully cleaned.
The end of the pipe should be treated with a file (make an input chamfer).
Apply to the treated surface lubricant to reduce resistance.

If possible, it is desirable to fasten the pipe vertically, for example, in plumbing vysieties, leaving free access to the upper part - the area of \u200b\u200bthe cut. It is necessary to correctly calculate the strength of fasteners in order not to deform the body of the pipe.

Then they take a pre-prepared knob with a draft rash (№1) the desired diameter and suitable thread characteristics.

Example cutting threads on water pipe Using a manual twist. Inside the working cylinder, the cut is inserted into the dice and is fixed with two (four) bolts located against each other

The tool is kept horizontally - perpendicular to the end area of \u200b\u200bthe pipe. Wear an inner hole a draft plate on the headband. Light pressure and sequential short turns of 25-30 ° make the initial incision.

This work should be performed carefully without hurry, constantly controlling the straight angle between the horizon of the dice and the vertical of the pipe.

This technique neatly cut the first two or three threads. Usually after cutting the first two-three threads, the tool firmly occupies the working position. Next, the straight angle can no longer control.

But cutting technology is short (without particularly severe traction) circular motions should be kept until the end of the cut. It is recommended to periodically add lubricant at the cutting point.

After the first pass, the device twisted and then repeat another one or twice already by piercing (No. 2).

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Method # 2 - Appliances Cutting Cuts

Klupp is a kind of the same dice for cutting threads, including pipes. The distinctive feature of the club is the ability to adjust the incisors.

Set of klupps under different size Pipe thread. Each of these devices is equipped with screws fastening blocks with cutters. These screws can additionally change the size of the thread diameter in small limits.

There are clouds for manual application, as well as similar devices with an electric drive.

Option # 1 - cut handmade. Cutting on pipes manually, as a rule, is performed by the clusp, which is installed in the ratchet holder. Such a holder makes the work on cutting the pipe thread comfortable and less complex.

Of course, depending on the conditions of the maintenance work, manual holders of other species can be used. For example, a standard retainer knob with two handles.

The principle of creating carved clupp is almost similar to the method of working with traditional dies:

Clear working surface Pipes, see the absence of defects.
Sand plot of cut to a species with a pronounced metal glitter.
Treat the external work part of the end edge at an angle of 45-60º (chamfer).
Lubricate the prepared surface with technical vaseline.
Secure the pipe in mechanical vice or hold the gas key.

After these procedures cutting tool (Klupp) Planning the inner hole on the pipe champper and with a moderate uniform juggle begin to rotate it with short return-transit movements.

The so-called "ratchet" is considered a comfortable snap-in to work with the cluster - the lever with the reverse idle. Using such a hand tool, it is easy to cut the thread on the pipe in different conditions Installation or repair

If a ratchet retainer is used as the holder, only straight-shock cutting is carried out. It should be noted the convenience of applying a ratchet retardation when working in cramped conditions.

For example, when it is required to handle the pipe laid in the immediate vicinity of the wall.

Option # 2 - Rem Electric Clus. Along with the hand tool, widespread applications are found with electrical drive. Obvious advantage For a locksmith - a significant reduction in consideration.

But on the other hand, not all electric cars Capable to ensure the production of works in cramped conditions. In addition, when working with a manual instrument, it is possible to obtain a better result.

To obtain a similar result from electric clubs, a rich experience of working with this tool is required.

Equipment for a clusp, complemented by an electrical drive. A modern effective tool that significantly reduces the physical load of the locksmith. True, electric clusp is more often used in the professional sphere than in everyday life

Work electric clupp:

Preparation of the surface of the pipe in the area of \u200b\u200bthe cutting - cleaning, chamfer, lubrication.
Fixing the pipe with devices capable of ensuring hard fixation.
Fixation at the starting point of the Clamp Dice Holder, which is supplied.
Check the stroke and direction of rotation of the clus.
Cutting the first two-three turns in the jogging mode.

At this point, the appliance action is stopped, turns on the function of reversing rotation and the jogging of the pipe with the tube. Must be able to periodically clean the area of \u200b\u200bthe cut during the entire process.

Method # 3 - Using lathes

Large-scale construction repair workAs a rule, exclude the use of a manual tool. Here, lathes are commonly used for appropriate pipes.

Thread-cutting functions are supported by many universal actuators.

For the manufacture of threaded parts on pipes different diameter Turning machines are used. On the lathe you can make a thread of any configuration

With the help of machines efficiently and easily made both internal and external pipe threads. Fastening pneumatic (or mechanical) module turning machine Provides quality reliable fastening Pipes, and accurate supply of the treated part to the cutter.

To perform thread-cutting functions apply different types Cutters:

rod,
lamellar
insert.

Performance of work on lathes produce specialists trained by such a matter with appropriate qualifications. Without experience and professional skills, try to cut the thread with their own hands on the machine is not recommended.

To homemade masters, who decided to do a locksmith and make a carving on metal blanks, the following tips will help in the work:

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Selection of drill diameter, to carry out cutting it is better to produce according to the regulatory tables specified, for example, in GOST 19257-73

Metal strip, corner or profile pipe Before carrying out cutting, you should prepare: Clear rust, if necessary, remove irregularities with a file

When cutting it is very important to make it gently and correctly make 3-5 first turns. Then the tool "becomes on the move" and for the correctness of the cuts of the turns can no longer worry

A few words about GOST on pipe thread

In working with gaseous and liquid media, according to GOST 6111., if necessary, the introduction of disconnect connections in the pipeline scheme is allowed to manufacture such compounds on a thread basis.

It is possible to execute not only pipe, but also a conical thread ( GOST 3662.).

An example of the production of conical tubular thread on a technological adapter. Similar techniques are used in the plumbing often. On operational indicators, the conical carving is allocated in best side relatively other species

Despite the rare application of conical threads in pipe connectionsIt is considered more convenient in screwing / swing characteristics.

It should be recalled that the angle of tapered threads is directly related to parameters such as a step and diameter. The permissible value of this angle cannot be less than 26 °. The standard value of the top of the profile on the conical thread is 60 °.

Pipe threads are distinguished characteristic feature - They have a rowed top of the profile. When complying with cutting standards, the magnitude of the rounding is 10% of the size of the thread radius.

With such a technology, cutting can achieve a significant reduction in internal stresses on small Square Metal occupied by a threaded profile.

Installed tolerances GOST 6357., along with cylindrical and conical carvings, execution on pipes metric thread.

Here the tilt angle standard is 55 °, which causes an increase in the number of turns on the area along the length of an equal part with another type of thread.

The result is a compound with a higher degree of tightness, but the complexity of using such compounds is increasing.

Metric thread and full technical alignment according to standard parameters. For metric threads, the unit of measurement is used - millimeter, while the pipe is usually measured in inches

The existing installations of GOST also provides for the possibility of execution of persistent and trapezoidal thread on pipes. But in practice, these types of cutting are not used due to their low operational strength.

In plumbing work apply different methods Pipe connections. The choice of method depends largely on the material of the pipeline and its "zone of responsibility". The threaded docking of parts is recommended to be used in areas available for periodic revision.

Information for alternative ways Compounds of pipes are presented in articles:

Knowledge of the creation, operation, maintenance threaded connections On pipes are always relevant for every person who are engaged in the economy, plumbing, other engineering communications.
Without this information, it is impossible to produce quality repair, upgrading pipelines, simply support the work of household economic systems.
Have something to add, or have questions about cutting threads on pipes? Please leave comments to the publication, offer your ways and effective tools To create a thread. The form for communication is located in the bottom block.

Cutting internal thread The tag starts with the selection of the desired tool.After the first step is to drill holes. In fact, this stage is the most important thing, since if it is mistaken with the selection of diameter, then either the bolt will hang out, or when cutting the thread from overload broke the tap. It is best to determine the diameter of the holes in the tables, but it is possible to produce a rough estimate: using the thread diameter, its step can be obtained by the approximate value of the required diameter of the hole.

For example, if external diameter Threads 18 mm, and pitch 1 mm, it is required to drill a hole in 17 mm. It is necessary to drill strictly perpendicular to the surface of the part (due to deviations there is marriage when cutting). The drilled hole is desirable to make a small chamfer. At the deaf holes, the depth should be greater than the length of the cut part so that the tool during cutting is over the limits of the required thread length. If this stock does not foresee, then the thread will be incomplete.

Detail S. drilled hole Fix in vice. The tap is fixed in the gate (in the absence of an adjustable key) or the cartridge of the machine. On the quality of the thread, the cutting speed and the durability of the tool considerably affects the correct selection of lubricating fluid (coolant). In order not to spoil the tool, and get a thread to get pure and with the right profile, you need to apply the following coolant:

diluted emulsion (one part of the emulsion, mixed with 160 parts of water);

for details from brass and steel can be used linseed oil;

for aluminum products - kerosene;

for details from red copper - can be turpentine;

in the products of cast iron and bronze, cutting should be carried out dry.

It is impossible to use mineral and machine oils - they contribute to a significant increase in resistance, which the tool is overcome during the work, have a negative effect on the roughness of the thread and lead to the rapid tip wear.

1.2. Rules for cutting the internal thread by the toll

With manual cutting of the thread, the tool is inserted into the hole vertically (without skew). The knobs rotate in the right direction (for the right thread clockwise) not all the time, and periodically make 1-2 turns in the opposite direction.

With such a rotational return movement of the tap, the sliced \u200b\u200bchips breaks, becomes short (crushed) and easier is removed from working area, and the process of forming the thread is much easier. At the end of the cutting, the tool is turned to rotate the turn in the opposite direction, then it is driven through the finished threads through or up to the stop for the deaf holes. You must also follow the following rules:

When forming a thread in viscous and soft metals (aluminum, copper, babbitt and others), as well as in deep holes The tool should be periodically unscrewed from the hole to clean the grooves from the chips.

When using the tip set, you need to use all set tools. Slicing immediately by a clean tilt or middle, and then the Chernov does not speed up without passing, but only slows down and complicates the cutting process. In addition, the thread is obtained by poor quality, and the tool may break. The finishing and middle taps are screwed into the hole manually (without a turn) until the tool goes on the thread correctly, and only after that set the knob and continue to work.

In the process of cutting, it is necessary to carefully monitor the correctness of the tool insertion so that it is not skewed. To do this, it is necessary through every again chopped 2-3 chip threads to check the position of the tap relative to the upper plane of the part with the helm. Especially carefully work with deaf and fine holes.

Design of the tester

Tap (Fig. 1) is a tempered screw, on which several direct or screw grooves are cut, forming the cutting edges of the tool. Grooves also provide chips formed during cutting chips can be output from the cutting zone.

The tap consists of two parts - Work and shank, at the end of which the square is made (at hand testers). The working part of the tester includes: cutting (intricate) part, which ensures the removal of the main part of the processing allowance; calibrating part that performs the final processing of the thread; shake grooves; Feathers (thread turns separated by chip grooves) and core, providing a toll sufficient strength and rigidity for processing. The tail part of the tap serves to fasten it in the gate, which produce workers and idle movement of the tap.

The working part of the tap is manufactured From the instrumental carbon steels of stamps U11, U11A, high-speed steel or solid alloy. The choice of material of the working part depends on the physico-mechanical properties of the processed billet. In solid testers, the material of the tail part is the same, and in testers consisting of two parts connected by welding, the tail portion is made of the structural steel grades 45 and 40x: the number of stroke grooves made on the tumbled depends on its diameter (three grooves of Diatechik diameter up to 20 mm and four - for taps with a diameter of more than 20 mm).

The main work when cutting the threads perform cutting edges formed by the intersection of the front surfaces of the groove with the rear (hidden, made on the archimedean helix) surfaces of the working part. The population of the rear surface of the cutting teeth allows you to save their profile constant after a hearty, which is carried out centrally in the sharpening shops.

As a rule, taps are manufactured with straight grooves, however, to improve cutting conditions and obtain accurate and clean threads using taps with screw grooves. The angle of inclination of such a groove to the axis of the tap is 8 ... 15 °. To obtain accurate and pure threaded surfaces in through holes in the processing of soft and viscous materials, torn -anny taps are used.

Fig. 1 tap:

a - Design: 1 - thread (turn); 2 - square; 3 - tail; 4 - groove; 5 - cutting feather;b - geometrical parameters: 1 - front surface; 2 - cutting edge; 3 - a hidden surface; 4 - rear surface; 5 - cutting feather; α - rear corner; β - cutting angle;Δ - an angle of acuction; γ - front angle; b - with a screw shake groove: 1 - groove; g - cutting a deaf thread; ω - the angle of inclination of the screw groove.

As you know, the thread can be cut in holes or on rods, for which there are two of various types Tools for cutting - taps and dies, respectively.

Cutting threads in holes

To cut the threads in the hole, you need a set of taps-hive and clean. First, the hole of the required diameter is drilled (see the table of holes for the thread), and the carving of the draft tank is carried out (one groove is applied). Then we pass the threads already with a clear tag. The square shank of the tap must be securely fixed in the gate. In order to cut it easier, the hole is lubricated with technical oil (solidol, for example). It should be remembered that the deviation of the diameter of the holes from the specified in the table at least 1 mm will lead to poor-quality threads, marriage.

Cutting threads on rods

In contrast to cutting the threads in the hole, the rod carving takes place at one time with one pier. The dice has a central hole that cuts the threads, and the peripherals that form the edges and remove the chips. The plate is also fixed in the gate, lubricate the rod with solidol and gently screw into the rod. If the cry is hired, you need to make two turns in the opposite direction, then continue to cut. Before winding the end of the rod give a cone-shaped form using a file, so that the thread is cut without sinking. The diameters of the rods under the thread you can see on the table.

To determine the desired hole diameter to cut the thread, the table is the most convenient tool. It is possible to produce mathematical calculations for this purpose, but if the table is compiled according to GOST, there is no need for unnecessary manipulation.

The threaded hole is used to create detachable connections. But if it does not occur with the outer cutting problems, since any necessary fasteners made according to GOST can be purchased in stores, the internal thread requires a more thorough approach;
To cut the internal metric thread sizes M4, M5, M6, M8, M10, M12, manual tools or specialized machines are used;
To obtain a metric inner thread, it is required to perform an appropriate hole for future threads in the workpiece;
The performed holes for metric cuts must correspond to the diameter of the tool, which serves for cutting;
Each hole performed provides the need to use a defined tool;
For these purposes, the master is obliged to competently select the diameter of the drill drill under the thread cut;
Cutting large holes big diameter Specialized machines are used. In them, drills are characterized by a conical type of shank;
Conventional drills are equipped with a cylindrical shank;
The size of the cone directly depends on the size of the drill. The larger the diameter of the drill, the greater its cone;
If necessary, cutting the internal thread type M4, M5, M6, M8, M10, M5, M6, M8, M10, M12, the diameter of the required opening is selected based on the diameter of the thread and the thread steps;
To determine which size must have a diameter, requires deciding with the size of the holes. To simplify this task, a special table is used, compiled according to GOST. This means that the table provides for the execution of standardized operations. Due to this, it is possible to obtain the same type of products that are suitable for various kinds of threaded connections.

Focusing on the table and following its parameters strictly, you can perform internal cutting of the desired diameter, and hardware, acquire bolts in a specialized store. In this case, the connection will be perfectly selected.

Types of cutting

The thread externally resembles the screw grooves with a constant cross section. At the same time, the thread is divided into two types:

Internal;
Outdoor.

The threaded connection has a wide scope of application. It is problematic to find places where it is not used. Due to the threads, the details are attached to the rotation, translational movement, fastening. Almost all mechanisms, machines and nodes necessarily include a threaded connection.

At the same time, cutting divide into two large groups:

Overcoming cutting;
Multigipical threaded connection.

Depending on the direction of movement of screws on the thread, it is divided into:

Left-sided;
Right-sided.

If you take into account the size standardized sizes, cutting can be divided into three more types.

Pipe. Its distinctive feature is the original diameter that focuses on the size pipe hole. In this situation only outer cutting is carried out.
Metric. It is characterized by a profile made in the form of a triangle. The profile angle can be 60 degrees. Dimensions are determined in millimeters. If the step is large, the marking includes numbers and letter values. The figure is the magnitude of the outer diameter. If the metric carving has a non-standard small step, then to lettering design Type M4, M5, M6, M8, M12 add a number that indicates step. In this situation, marking is presented as M6X0.6.
Inch. In inch types of thread a distinctive feature Performs the value of the corner of the profile. For inch types, it is usually up to 55 degrees. The magnitude of the opening is indicated in inches, and the step depends on the amount of the threads.

Taught

The tap is the main tool designed to cut the thread. In this case, the taps can be manual or machine. According to this characteristic, it is determined whether the tap is applied to manual tool or is used as a working tool of a specialized machine;
Hand-type taps are produced by sets;
Typically, the kit includes three testers;
The first two taps from the set perform preliminary measures, and the latter brings the thread to the required piston state;
Using the tavercover tap, it is possible to get optimal in size and shape of cutting;
Each tap has its own number indicated on the shank;
In some cases, testers included only two, where the first is preliminary, and the second is purple;
Taps are made on the basis of high-alloy steel, which allows them to work with solid varieties of metal;
To perform outdoor threads, a special dice is used;
The plate is round or prismatic.

Inner slicing

To equip the workpiece with a hole for the internal type thread, the first thing should competently select the drill size for M4 or other threads according to GOST.
By choosing a drill, the master starts to perform holes for the thread.
To proceed to the use of a special tap for cutting M4, first the performed hole is processed by the zenker tool. This allows you to achieve the desired cleaning of the hole.
In the process of cutting grooves in a metal workpiece, the material is a bit squeezed. Because of this, it is important to correctly select the size of the drill. The drill is used slightly more than the internal thread diameter of the tool used.
When working with an elevated hardness metal, it is not possible to significantly change the values \u200b\u200bof the hole in the formation of the grooves due to the material characteristics.
If the metal or small hardness processing is performed, the dimensions of the hole made are changed strongly. When the magnitude of the opening with an internal threaded diameter, active extrusion will begin in the processing process. Surplus will adversely affect the tap. The tool will begin overheat, the chips stick to the inner surfaces. As a result, you will get a thread with incorrect grooves, plus a lot of risk breaking your tap.
To determine the diameter of the suitable drill, a specialized table is used. It is clearly indicated by all major parameters, which allows the newcomer to quickly understand all the nuances.

Table

The table consists of several basic columns.

The first indicates the dimensions of the metric thread. It happens from M2 to the maximum value of M48;
The second column is a place where a major step is indicated. It is used for each size of the metric thread. Moreover, depending on the diameter, the step is different, gradually increasing as the diameter of the thread increases. When you cut the grooves, focus on these parameters;
The third column indicates the diameter of the drill (holes) under the metric cutting with a large step.

Sometimes it may be necessary to use a small step, which happens quite rarely. But in this case, a separate column is provided in the table, on whose indicators should be guided in such situations.

About how to chop the thread by the tag manually, each person associated with the installation of metal structures or performing various repair work should know. This is one of the basic fastest skills, which experienced workers have been brought to automatism.

The taps are intended for reaching the rotating tool (gate) or fixing in the cartridge of the machine.

Basic instrument

To perform internal threads manual way Various testers are used made of carbon or high-speed steels. They are a metal rod with a working part and a shank designed to cover the torque tool (gate) or consolidation in the cartridge of the machine. The working part with an outer thread has a conical shape, longitudinal grooves are provided for the release of chips in it.

There are several type varieties, but not all of them are suitable for manually performing internal threads. For example, machines can only be used on machines due to their design. For production hand work Suitable the following types of testers:

Complete. From the title it follows that this is a set of several products (3-5 pieces) of the same diameter used alternately. Allow you to achieve a clear thread profile, although the operation takes some time.
Machine-manual. The variety of machine tools in which the end of the shank has a rectangular cross-section for covering the gate. The thread is cut in one pass.

In addition, taps may have various execution Depending on the type of thread. Most often occurs metric, less often - cylindrical and tubular.

As a rule, when installing metal structures production buildings (hangars, greenhouses and other structures) not subject to vibrations, metric threads are used.

Also, a part of the testers is manufactured with a cut working part, it is necessary to work with deaf holes. Separately, it is necessary to consider work with alloyed steels of high hardness. Products for overcoming this hardness have the working part of the grooves located in a checker order either crosswise.

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Selection of drill

The electric drill is necessary to perform work on cutting the inner thread.

Before chopping the thread by the tier, you must first drill the hole under it. It is quite clear that the diameter of the hole should be less size tap, but how much? Exists universal way Calculations of this difference. Any thread is characterized by two parameters:

diameter, indicated on tools with capital letter M ahead, for example, M6;
the turn of the turns is registered in the form of a number after the first parameter, for example, M6x1.

Looking at the marking of the tap, it is easy to choose a drill to work. It is necessary from the diameter value to take away the thread step, in the example of M6x1 it will take a hole with a size of 6 - 1 \u003d 5 mm. The drill should take the usual cylindrical, for the processing of the metal are made from high-speed steel P6M5. In order to facilitate the selection of sizes in Table 1, the recommended diameters are presented for the holes of the most "running" metric threads Profile.

Table 1

Marking	M3.	M4.	M5.	M6	M8.	M10.
D holes, mm	2,5	3,3	4,2	5	6,75	8,5

Insofar as we are talking about manual processing Metal, then when selecting drills, one particular feature should be taken into account. When working S. electric drillNo matter how trying to keep it smoothly and motionlessly, the hole will be broken and its size will be somewhat more than necessary. As a result, after passing by the tag, the thread turns will have a cut profile. When twisting the bolt there, the backlash will appear, and at a high moment of tightening the coils may simply deform. The quantity of the hole depends on two factors:

Zenkovka is needed to remove the champers on when cutting the inner thread.

Diameter than it is more, the stronger the hole unfolds. For example, at d \u003d 5 mm, an increase of 0.08 mm occurs, and at d \u003d 10 mm - already 0.12 mm.
Working conditions. The locksmith may be in an inconvenient position or at height, it will cause an increased opening, which will later affect the quality of the connection.

The problem is solved as follows: so that the internal thread turns out to be full-belly, it is necessary to initially take the drill, the diameter of which is 0.1 mm less required. It is possible that in some cases the rotation of the tap will be difficult, but usually no difficulties arise.

Preparation of tools

To perform work on cutting internal threads, you will need:

markup Means (Roulette, Line, Pencil);
electric drill with drill set;
zenkovka for refoil removal;
a set of taps with a manual gate;
a hammer;
kern.

The drills should be fed (sharpened) in accordance with the hardness of the material being processed. What he is harder, the more you need to withstand the angle of sharpening. During drilling and cutting the working parts of drills and testers, you must be lubricated. The choice of lubrication type depends on the viscosity of steel. For steel, an old fat or solidol is suitable for steel, for stainless steel - machine oil.

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Procedure for the production of work

To properly perform the entire complex of work on cutting the thread, it is recommended to adhere to a specific sequence. It is important when you need to provide good hundreds of connections as when assembling metal structures. It is necessary to start with markup, which is performed using a roulette or a ruler according to the drawing. Missing the specified distances from the base sides, at a found point put a pencil label. Marking is performed for all holes immediately or for those where the employee is capable of reaching, being at the height.

Next, putting on the scheduled place of Kern, one designed and accurate blow is applied to make a clear deepening. Naturally, before the start of the procedure, the core must be sharpened properly. In the same way you need to outline all the places of future holes. Then the drill is fixed in the cartridge drill and is lubricated, after which you can proceed to the hole to do. Drill turnover must be adjusted in advance so that they are low.

Drilling is carried out carefully, with a middle pressure, holding a drill without skewed at an angle of 90 ° to the surface. It is impossible to put the power tools in different directions, it enhances the breakdown of the opening. It is necessary to consider that at the time of the release of the drill, on the other hand, some effort will be required and a slight increase in the number of revolutions. If the metal is thick, then the lubrication of the working part must be carried out during the process several times. When all the holes are ready, Zenkovka is inserted into the cartridge and the chamfer is removed.

The last stage - cutting the thread. The sequence of performing this operation is the same for all types of taps. Climbing it in the gate and pre-lubricating it, the end of the tool is inserted into the hole, also observing an angle of 90 °. Slightly pressing on the knob from above, so that the first turns of the working part can cling to the head of the chamfer, make the first turn. Further rotation goes without push according to the algorithm: one turn forward, floor turn back to reset chips. With machine tags, performing threads in one pass, you must act carefully: the tool is fragile and easily breaks. Complete products go easier, but here you need to drive a thread by the first number, then the second and so on.