How to cut threads on a pipe near a wall. Methods for creating threads on metal pipes

Having a personal home in our time is a great success. It does not matter whether it is an apartment or a private house. In any case, the owner feels solid ground and confidence in the future. As a rule, in your own home you have to do a lot of work yourself. Well, for this you definitely need to have a personal instrument. Very often, owners of private houses are faced with the creation of gas and water pipes. It should be noted that this procedure requires not only skills in working with a welding machine. Very often it is necessary to create detachable connections for further disassembly of communications when repairing and replacing certain elements. But how to cut threads on a pipe? Today we will try to give a full answer to this question.

What is cutting called?

Before considering methods and tools, let's figure out what this process is called. Cutting is the special mechanical processing of workpieces in order to obtain cuts on the outside or inside. The very result of the process consists of protrusions-coils and special grooves, twisted into a spiral, and alternating with each other.

Depending on where the threads are cut on the pipe, different tools are used. This process is performed on the following elements:

• nuts;
• bolts;
• pipelines with a detachable type of connection;
• parts of various equipment and mechanisms.

In turn, cutting can be internal and external. In this case, as is already clear, different tools and devices are used. Let's look at all the techniques in as much detail as possible, and start with the technique for creating an internal view.

Internal view

You need to cut the internal thread on a pipe with a special rod called a tap. It, in turn, is inserted into a special knob. The tap consists of a front (intake) part, which is located at its end, a calibrating part (the middle of the head) and a tail with a square profile for normal retention in the device.

It must be said that when converting from the metric system to the imperial system, three types of taps must be used, which cut at different depths.

The technology for cutting internal threads involves the following sequence:

1. The tap must be selected according to the cutting pitch on the element that will be screwed into the pipe.
2. Next, the tap is inserted into the driver;
3. The tap is positioned strictly along the longitudinal axis of the pipe so that everything is cut evenly and without bevels;
4. Squeezing the cutting element and the end of the tap together, you need to turn the knob;
5. Cutting is done to the marked depth with a small margin.

The process itself is much better performed on a machine, where the tap is inserted into a three-jaw chuck, and the element in which the cutting will be performed is fixed on a movable bed. This ensures exact alignment of the axes. Doing this manually is much more difficult. But, if the connection is not very responsible, then you don’t have to bother.

External type

External threads are created on bolts, rods and screws using a die. This is a special device in the form of a washer that has a hole in the middle. Dies are divided depending on their design into:

• solid;
• sliding;
• prismatic;
• round.

Solid devices are washers with a constant diameter, and they cannot be disassembled. Those. For each rod size you need to use different devices.

Sliding types, unlike solid ones, can be used with small changes in the diameter of the rod. At the same time, they are fastened in a clamp so that all the numbers on the parts fully correspond to the numbers on the frame itself. Also, a special plate is placed between the stop and the die, which prevents the housing from cracking from pressure.

Prismatic types are used when cutting on 32 pipes and other common diameters. They consist of two detachable parts, on which there are grooves on the outer sides.

The round die is installed in an easy-to-hold wrench and may have one or more special places for stop screws.

The most practical among these types is the sliding type. Due to the ability to change the internal diameter, it can cut on a wide variety of elements that do not exceed the general cross-sectional size.

It is advisable to say that cutting on a stainless pipe is quite difficult, since this type of steel has high hardness. Other metals can be easily processed by hand, which saves time and money.

What thread should I use?

When creating a detachable connection for water and gas communication elements, cylindrical pipe threads are used. As a transition element between them, special bends are used, which have an internal thread.

The last two turns, which are cut on the elements, are called runaway. They allow you to wedge the coupling in such a way that a rigid and durable connection is obtained, and using sealing material you can achieve complete tightness.

Most often, a long type of cylindrical thread is cut. The reason for this is frequent leaks through leaks and at the same time they are not visible to the naked eye. Water communications, unlike gas ones, can have a short cut type. It is also very widely used on large diameter elements to reduce the time required for twisting and cutting.

There are also cases when the turns are not cut, but rolled. This method is used in thin-walled communications for gas supply and heating systems. In this case, the critical wall size is allowed to be significantly smaller than when cutting.

Tools used

Today, the following types of clamps are used for external threads:

• pipe (usual type);
• Mayevsky's clamps;
• ratchet

Conventional clamps are used when creating coils with your own hands. They are also used for small volumes of work performed. When cutting, sliding and non-sliding dies are used.

Pipe fittings are manufactured in two types:

• for diameters from 15 to 20 mm;
• for diameters above 25 mm.

The instructions for cutting with pipe clamps are as follows:

1. First you need to clamp the pipe in a vice, or clamps.
2. Next, its end must be cleaned of rust and other contaminants.
3. The cleaned end is lubricated with drying oil.
4. Next, a clamp is put on the pipe and, using blows with a mallet, it is seated in place.
5. Once you are sure of the correct location, you can begin rotating to cut grooves to the required limit.

You can also often find such a device as Mayevsky clamps when creating coils. Dies for it are produced in two versions: No. 1 (15 and 20 mm) and No. 2 (25 and 32 mm). For other diameters, it is best to use the usual, above-mentioned clamps.

Among the advantages of Mayevsky's die, it is fashionable to highlight light weight, simplicity of design, ease of maintenance and the ability to hot-swappable dies. It should be noted the importance of accurately installing them in accordance with the marks.

The ratchet type of this tool is used for element diameters of 15, 20 and 25 mm. For maximum convenient use, such devices use a ratcheting mechanism, which allows cutting on elements that are located in hard-to-reach places. With a diameter of less than 25 mm, everything is done in one pass. In other cases, a double pass is required.

Features of care

When using screws when cutting threads yourself, you must carry out proper care of this tool. So, upon completion of the work performed, they need to be disassembled and completely cleaned of chips and other unwanted contaminants. Next, it is recommended to lubricate the entire body with mineral oil so that rust does not appear on it and the rubbing parts “stick” to each other.

A prerequisite is to clean the instrument from dust and dried oil approximately once every 2-3 weeks, so that in the future the instrument does not crunch when used. To perform this procedure, experts recommend using the following technique:

1. Using a rag, everything is cleaned of visible contaminants that appeared while it was lying there.
2. Next, a caustic soda solution is made. The proportions are taken as follows: for one ten-liter bucket of warm water, 0.5 kilograms of dry matter is calculated.
3. Before washing, you should completely disassemble the instrument.
4. After the procedure, all parts are lubricated with oil and collected in a pile. It is advisable to then wrap the instrument in a rag or polyethylene to further protect it from contaminants.

Clips with dies should be stored in a dry place and closed. A small layer of lubricant will reliably protect the metal from rust and significantly extend its life.

To summarize and figure out how to cut a thread on a pipe, we can say that this procedure is performed using taps and dies. The first ones have no types and are selected separately for each internal diameter of the pipe. Dies can be either standard sizes, without the ability to change the diameter of the threaded hole, or with interchangeable values. Everything here depends on the type and type.

With the help of special devices called clamps, the cutting process can be significantly simplified. But, for normal operation, mandatory care is required for all instruments. They must be clean, lubricated and always ready for use. To do this, it is recommended to carry out prophylaxis once every 2-3 weeks.

Home craftsmen today don’t often think about how to cut threads on a pipe. Most projects are implemented using alternative materials. But such a need sometimes arises. Thanks to basic skills, you will be able to independently carry out simple repairs at home or in other conditions.

Basic Concepts

A threaded connection is essential if it is necessary to install a shut-off valve, adapter tee or coupling on a metal pipe. Very often joints become unusable and have to be redone. The thread is characterized by:

• depth;
• walking;
• profile;
• profile angle;
• location.

Depending on the profile and pitch, threads are distinguished:

• Inch. Has the shape of a triangle. It got its name from the units in which the outer diameter is measured. Used in the assembly of plumbing and heating parts. Conventionally, they are divided into pipe and fastening. The second has a larger pitch to ensure better fixation.
• Conical. The main use of this type is to ensure that the connection is sealed without the use of various sealing materials.
• Cylindrical. This is a type of inch thread with a finer pitch. The upper edge of the profile is smoothed and resembles part of a cylinder. Usually the thread pitch coincides with the inch pitch for parts of suitable diameter.
• Trapezoidal. Has an apex angle of 30°. Most often used in bolted connections to provide greater reliability during fixation. A thread whose sides resemble an isosceles trapezoid is called persistent.
• Rectangular. Used for the same purposes as the previous type.

Note! The last two varieties belong to the metric class. They can be cut into small diameter pipes that are used in specific tools.

Based on the location of the cutting, the following are distinguished:

• external;
• internal.

Each of these types requires an individual approach and is intended for specific purposes.

Preparatory stage

The quality of the final product depends on how responsibly this stage is completed.

• The tool that will be used to perform the work must be in good condition. There should be no rust on it. For this purpose, during long-term storage it is coated with a preservative lubricant. Clupp cutters must be well sharpened.
• If the pipe has already been in use and there is paint on it, then it must be thoroughly cleaned. This is done with a file, grinder and grinding wheel, sandpaper or hair dryer.
• Using a grinder or hacksaw, the plane of the end is drawn out. To do this, a small piece is cut off to create a right angle relative to the axis.
• The burrs are removed with a file.
• The chamfer is removed in such a way as to create a small cone.

All work is done with a die or a ladle. These are identical concepts and are synonyms. Depending on the design they can be:

• Adjustable or sliding. Usually they contain several incisors, the distance between which can be changed. They are especially useful in cases where the pipe profile is uneven due to deformation or manufacturing defects, but threading is still required. Most often they are installed in clamps that provide them with good fixation. With the help of such products, threads can be cut in several passes, which increases its accuracy and quality.
• Monolithic. They are a small cylinder with a hole in the middle. Such a tool is clamped into a special die holder. Usually secured with one or more bolts. With this tool, cutting is made in one pass.
• Conical. Designed for cutting the corresponding threads mentioned above.

The lathe is selected depending on the diameter of the pipe being processed, as well as on the direction of the thread - right or left. All designations are applied to the packaging or directly to the instrument itself. The whole process will boil down to the following steps:

• The workpiece is fixed. If it is not secured in any system, then it is clamped in a vice. In the case when cutting will be done on a water pipe or heating pipe, it is necessary to make linings to immobilize it.
• The end of the prepared pipe section is lubricated with machine oil or grease. If these components are not available, then you can use what you have on hand - even lard.
• The surface of the tool cutters is also lubricated.
• The die holder with the leech is brought to the end of the pipe. This must be done exactly at a right angle. This is much easier to do with a die holder with a guide.
• At the same time, it is necessary to rotate the thread cutting tool and press it against the pipe. Coupling has to happen. Thus, it is important to cut the first 2 turns.
• If you do not use a die holder with a guide, you will need to constantly ensure that the angle remains 90°. If you do not comply with this requirement, then a imbalance may occur. This threatens that the thread will be torn off, the tool will be damaged, or the required step will not be observed.
• Do not cut in a continuous pass. The process will produce metal shavings. In order to remove it, you need to make one turn in the direction of movement and half a turn back. It is thanks to this that accumulated waste will be removed.
• As you progress, you also need to add lubricant.
• After completion, you need to unscrew the eyeliner and go through it again to make the final liner.

Note! In order for the final result to be much better, two dies are used. One of them is called draft. Its purpose is to quickly lay out the path and marks for the next element - the finishing one. Thanks to the second die, the perfect cut is obtained.

Thread cutting using a die uses the same mechanism. In addition to this, some products have the ability not only to move the cutters, but also to rotate them. In this situation, you can use the same tool to perform both finishing and roughing passes. When using such a unit, you must be very careful during the initial stage. This is due to the fact that thanks to the ratchet handle, you can apply more force than with a conventional leash holder. If you don’t set the angle correctly at the very beginning, then you can ruin the entire workpiece and not even notice it. The clamp is inconvenient to use in cases where the pipe is already installed and is close to the wall. You will need to either bend it using a wedge or hollow out part of the plaster so that the nozzle fits well and does not move.

Using a power tool

An electric thread cutter can carry out the planned work several times faster, and the quality of the final product will be much higher. The sequence of work will be as follows:

• The pipe is cut to the required size. The most acceptable result is obtained when using a reciprocating saw with a guide.
• There is no need to remove the chamfer, as for the chamfer. By the way, this rule is also relevant when using a manual clamp.
• A special holder is placed on the pipe. He acts as a guide. It is important to clamp it well.
• The power tool is brought in and inserted into the receiver of the holder. The clamp is put on the pipe.
• Lubrication is carried out using a special composition.
• Then the unit does everything automatically.

There are times when to assemble a structure it is necessary to cut an internal thread in a pipe. For such purposes, a completely different tool is used - a tap. It is a small metal pin, at one end of which there are external incisors. To ensure everything goes right, you need to follow these steps:

• Using a caliper, the internal diameter of the pipe is measured.
• The corresponding tap is selected exactly based on this value.
• All burrs are removed using a file.
• The surface is treated using a metal brush.
• Tap number 1 is clamped in the holder and inserted into the pipe. It will remove 70% of the material during the pass. The remaining 30% is removed with a number 2 finishing tap.
• In order to remove chips along the way, the same rule applies as in the case of a lecher.
• If a thread needs to be cut in one of the pipe walls, then a hole is drilled with a drill. The drill must be clearly perpendicular. This is important, because otherwise you won’t get high-quality cutting.

Note! If the pipe is in the wall, then the thread can be cut so that a few millimeters of the protruding pipe are without it. It is necessary to leave such a gap so as not to tear the product when screwing in the connector.

Nuances

There are some secrets that have been developed over the years and are rarely talked about. Here are a few of them:

• You can make your task easier when using an ordinary leveler with a special guide. It is a small clamping mechanism with a thread at the end. It must be inserted into the middle of the pipe until it stops against the side and the jaws must be opened. The die is screwed onto the thread of the clamp and then goes smoothly and accurately along the pipe.
• Some craftsmen recommend using dishwashing detergent as a lubricant. No matter how absurd it may sound, it provides excellent passage, and the chips are not torn, but solid, which indicates the best quality of the work done.
• If you plan to install a brass tap on a steel pipe, you need to cut the thread so that when screwing on the locking mechanism, you get 4-5 turns. This will guarantee good fixation and long service.
• The design of the die is such that the thread is slightly conical, i.e. the last turns are less deep than the first. In this case, the bends are not wound completely. To compensate for such a deviation, it is necessary to walk after the clamp with another ordinary leer.
• There are situations when a thread needs to be cut on a pipe that extends a short distance from the wall. In this case, you can use a ruler or trim the die guide. This will not affect performance, but will provide greater convenience.
• When replacing cutters in a die, be sure to follow the sequence in which they should be installed. Most often they have numbers on them that correspond to the receiver.
• If the thread needs to be cut on a pipe that is recessed into the wall, then you need to do this. A small area is knocked out around the pipe to accommodate the plug. You can rotate the slicing mechanism using the T-shaped handle. A hexagonal head with slots is placed on its end. It is selected in such a way as to enter through the external hole of the die and cling to the space between the incisors.

Using the methods and methods listed above, you will definitely get an excellent result, which you will achieve with your own hands. If you know some secrets about where to cut threads and how best to do it, share them in the comments to this article.

Video

The technology for cutting threads on a metal pipe is demonstrated below:

Independent thread cutting on pipes of various classes requires the performer to have certain skills and knowledge of all the intricacies of this procedure. In this article we want to introduce you to how to cut threads on a pipe with your own hands (on a water pipe, on a stainless pipe).

Mastering the technique of thread cutting will allow you to independently repair water supply and heating networks, as well as any household appliances that include pipe products.

Threading techniques

The technique of cutting threads on pipe blanks involves the use of the following techniques:

• use of special threaded combs and cutters;
• rolling threads using round (flat) dies;
• preparing a threaded connection using “classic” taps and dies;
• thread cutting using special cutters.

Thus, preparing threaded connections at home is possible only if you have certain devices and tools. In the article we bring to your attention, we will consider in detail the method of cutting threads using a special thread-cutting kit (the so-called “klupp”).

Tool composition

An electromechanical thread-cutting kit called a die is used in conjunction with a set of radial dies of various diameters designed for cutting threads on pipe blanks of any size. In addition to the device itself, you will need the following tools and materials for threading:

1. Taps for quick cutting of internal threads.
2. A mechanical vice used to hold pipe workpieces.
3. A grinding machine designed for preparing thread cutting areas.
4. Lubricating oils.

We immediately draw your attention to the fact that working with an electric grinder is only allowed with gloves and safety glasses.

The procedure for cutting external threads on a water pipe

First of all, using a grinding machine, a part of the water pipe with an old thread or a section damaged by corrosion is cut off.

To form a high-quality cut, guaranteeing the convenience of all subsequent operations, immediately after marking, the pipe section is firmly fixed using a gas wrench or clamped in a vice. Next, a thin chamfer is cut off on the prepared section of the pipe, which significantly facilitates the rotation of the die. To facilitate its sliding along the thread, the cutting area is lubricated with machine oil.

During the threading process, the die holder rotates clockwise; but after the formation of several threads, the direction of its rotation is reversed. Using this technique allows you to free the working area from waste metal shavings.

The length of the threaded connection should not exceed 1 cm, which corresponds to the standard for most household pipeline networks. At the end of the thread cutting procedure, the treated area is cleared of metal shavings and then thoroughly wiped with a rag or rag.

Threading of internal threaded connection

Before cutting threads on the pipe in its internal cavity, you will need to measure the diameter of the pipe hole. Based on the data obtained, you can select a working tool (tap) of the required size. Make sure that the length of the pipe section protruding from the wall is several millimeters longer than the threaded part being cut.

Once you have finally decided on the required diameter of the internal hole, you should drill it to a size convenient for cutting threads.

During the drilling process, you need to carefully monitor the position of the inserted part of the drill, which should not deviate from the vertical.

Upon completion of the preparatory operations, a tap of the required diameter is inserted into the pipe hole while simultaneously rotating its base clockwise. Rotation is carried out using the so-called “wrench” included in the tool kit.

The procedure for preparing internal pipe threads involves the use of the following working tool:

• tap under the designation No. 1, intended for preliminary (rough) “running” of threads. The design of this tap is such that when using it, up to 70% of the material is removed;
• tap No. 2, used for final (finishing) thread cutting. With its help, the remaining 30% of the pipe material is cut off.

Thus, to obtain a high-quality and complete thread, you will first have to “walk” through the internal cavity of the pipe with tap No. 1, and then repeat the same operation using tap No. 2. All of the above work must be accompanied by the introduction of small portions of machine oil into the work area.

The principle of thread cutting is no different from the usual situations described above. The only difference is that it is extremely inconvenient and problematic to perform this work near the wall. For example, sometimes it is necessary to slightly hollow out a section of the wall near a pipe. It is very important to make the cut carefully. If it is uneven, it will be difficult to cut, and considering that you have already made a recess in the wall, cutting the thread will be extremely difficult. You can use a die to complete this task. First lubricate the pipe and die, and then start cutting the branches.

If the pipe near the wall has a large diameter, then the task of cutting threads becomes more complicated. In such circumstances, it is necessary to use not a die, but a die. For convenience, it is better to use an electric socket.

As for cutting threads on a stainless pipe, the task is complicated by the fact that the metal used is quite hard. Therefore, for cutting, you should select the appropriate grade of steel dies. In this case, marking P18, or better yet P18F2, would be a suitable option. The letter “F” means that the material contains a regulating additive of vanadium up to 2%. In addition, dies marked P9 can be used to cut threads on a stainless pipe.

If you choose a die of the wrong brand, you may end up without a die and without a thread. In some cases, it is only possible to make a thread on the shaft with a cutter.

Video

Instructions for cutting threads with a die:

Threading is one of the main types of fastening of metal pipes, which can be reproduced independently. So, next we will consider which tool for cutting threads on pipes is worth purchasing, and how to use it. But before this, it is worth deciding on the basic concepts, without which the work will be impossible.

What should you know about carving?

When installing shut-off valves, adapter tees or couplings on a metal pipe, a thread must be made, which is characterized by the following parameters:

• Depth- the distance from the base of the thread to the end of the pipe.
• Profile and its angle- cross-section of the coil, which is made in the form of a triangle, rectangle and other shapes. When the side edges of the coils intersect, an angle is formed.
• Step by step- the distance that is formed between the tops of the pipe or nearby turns.

Important: The larger the step, the greater the depth and number of turns per 1 unit. thread and therefore vice versa.

The determination of the profile and pitch should be treated with maximum attention, since the type of thread depends on this:

• Inch- appears as a triangle and is used when assembling elements of a water pipe, and sometimes a heating pipe.
• Cylindrical- a version of an inch thread that has a smaller pitch. The smoothed top edge of the profile resembles a cylinder. An example of an external cylindrical thread diagram is presented below:
• Conical- the type allows you to obtain a hermetic connection, which is especially important when using sealing materials.
• Metric- type is used for pipes of small diameters. It can be trapezoidal - the outer angle is 30 degrees, and the sides of the coil resemble a trapezoid. For bolted connections, rectangular threads can also be used, since they make the fixation more reliable. Here is a diagram of a metric thread, which looks like an equilateral triangle:

Preparing to Carve by Hand

Basic rules of use:

• It is recommended to clean the pipe at the thread cutting site from paint, dirt and rust (only metal should remain);
• if the pipe has a chamfer, you need to carefully remove it with a file (or a grinder, if you have the skill to work with this tool);
• During operation, the surface of the pipe and the cutter must be lubricated with a special substance (it must be smeared both at the beginning of work and during the process).

If you do not follow these rules, the service life of the tools is sharply reduced, and there is also a high chance of rejecting or simply breaking the pipe itself.

Step-by-step instructions for cutting threads using a die

A die for cutting threads on pipes looks like a nut made of hardened steel, inside of which there is a flower-shaped hole, the edges closest to the center are covered with sharp cutting surfaces, and “petals” allow the chips to be easily discharged without interfering with the work.

Working with the tool is not difficult:

• Firmly install the pipe vertically. It must also be prepared - cleaned of paint, chamfers, etc. The ratchet handle for cutting pipe threads holds a tool of the appropriate size, and you apply lubricant to the pipe.
• Place the die strictly perpendicular to the pipe. If there is a deviation of at least 5-10 degrees, then the pipe will already be damaged.
• Start moving the holder handle clockwise.
• When the required space is covered with threads, lift the cutter up and go down again over what has already been cut so that the grooves are clearer.

This video is a demonstration of the correct use of the die. Visual actions follow after the preparatory steps listed above:

Remember to periodically lubricate the cutter and pipe. Act smoothly and calmly. Do not pull the die while working and do not leave the process unfinished.

Threading set for pipes and rules for its use

An ideal option for home use is a pipe threading set. Klupp is a modernized die that has a special guide and ratchet. The tools in the set may be different, for example:

• Sliding. As a rule, they consist of incisors, the distance between which can be adjusted. Allows you to cut threads in several approaches, accurately and efficiently.
• Monolithic. The tool has a cylindrical shape with an internal hole and is installed in a die holder. Allows you to make carvings in one go.

Sets and individual components vary greatly in price and quality. There are budget options for sets for 1000 - 1100 rubles, and there are much higher ones.

Depending on the diameter of the pipe and the direction of the thread (right, left), the guide is selected. The further work process looks like this:

• The clamp is installed in the ratchet;
• oil is applied to the cutting part;
• a guide is installed on the edge of the pipe;
• the ratchet rotates, making threads;
• During operation, the edges and pipe are treated with oil.

It is necessary to change the die on time - it must always be sharp, and all other elements must be in good working order.

An example of thread cutting using a die is presented in the video:

Threading a pipe near a wall

You may have a situation where you need to make threads on a pipe that is already built into the wall. The principle of operation in this situation is exactly the same as described above. However, there is a big “but”: the device needs space to operate, so you may have to remove part of the wall. An example of such work is demonstrated in the video:

Important! The cut on the pipe must be made perfectly even, otherwise cutting the thread will be extremely difficult.

How to cut internal threads?

To manually make internal threads, taps are used that are inserted into the drivers. They consist of three parts:

• Zabornoy. Used directly for cutting;
• Calibrating. The middle part is necessary for guidance during sizing and cutting;
• Tail. The part has a square head and is used to hold the tap in the driver when cutting.

How to cut an internal trapezoidal thread can be seen in the video instructions:

Gutter cutting machine

A machine for cutting threads on pipes is unlikely to be needed by a person who is equipping his home. It's more of a working tool. In design, it is somewhat reminiscent of vertical drilling machines.

The diameter of the workpiece and the cutting pitch are adjustable. The operation of the spindle can be carefully debugged by adjusting the number and speed of revolutions. In principle, such a machine does almost all the work. Also, unlike manual lechers, the machine can make not only external threads, but also internal ones. More modern machines can process the smallest parts and products with thin walls.

In the following video you can clearly see how the machine works without distortions:

Video: Manual thread cutting in a country workshop

In the following video, the master will tell you in detail what needs to be taken into account for proper thread cutting, and how to do the job correctly:

Above we describe in detail all the main stages of work that both a beginner and a seasoned master need to know when cutting threads. However, if you understand that this process is not working for you, and you need to continue the repairs, it is best to contact a professional technician.

When performing various repair work that involves restoring water supply elements, replacing plumbing fixtures, heating registers, etc., it is necessary to use parts of metal pipelines with threaded sections. In this article we will tell you how to cut threads on a pipe yourself. If you know the features of cutting and stock up on the appropriate tools, then you will complete this task properly and relatively quickly.

Since time immemorial, for cutting threads on tubular elements, not metric, but so-called inch threads have been used, which differs from simple threads in a different thread profile angle (55 ? versus 60 ? for metric). In addition, inch threads have a smaller pitch value, which is explained by the small thickness of the pipe wall.

A small stroke indicates that there will be more threads on the same length of the threaded part. Accordingly, the reliability of the connection increases.

Carving is not uncommon right and left. On the right-hand thread, the turns, when viewed from the end of the product, go to the right, and, accordingly, on the left - to the left. Right-hand threads are much more often used.

It is very easy to find out which thread is on one of the threaded sections: if, when screwing on the joined element, it turns clockwise, it means the thread is right-handed.

On a water pipe, the direction of the turns does not matter, because the products do not rotate at the end of the connection, but remain motionless. In addition to pipe threads, fastening threads, which have a longer stroke, are also used in connections. It is performed on holes and hardware for them.

Pipe threading methods

It is possible to cut threads on water pipes with your own hands using two tools - a die (also called a lerka) and a die. What is the difference between them?

The die is a hand-held thread-cutting tool, the outer side of which has a seat for the body in the form of two oppositely located grooves. And the inner side is a plate with grooves and a threaded hole for removing chips, reproducing the pitch and diameter of the required thread. At the end of the threaded profile there are so-called runaway sections. They do double duty: they make it easier to center sections of two pipes before joining them, and they improve the yield of chips generated when cutting threads. The thread diameter is marked on the end surface of the die. For cutting, the die is inserted into a collar body, equipped with removable handles for turning the die, and secured with screws.

How to correctly cut a thread with a die? It is better if the pipe being cut is securely and evenly secured in a bench vice. The slightest misalignment will result in the thread being cut at an angle. This will lead to weakening of the pipe wall and distortion of the entire connected section of the water supply or plumbing system.

In order to ensure a reliable direction, make small modifications to the die. To do this, a guide bushing is welded to one of the ends of the die, which must fit into the pipe where the thread is cut with a small gap (no more than 0.2–0.4 mm). The length of the guide sleeve must be at least several diameters of the thread being cut.

Clupp is a more experienced thread-cutting tool (in most cases, a set of several clamps of different diameters is not uncommon on sale). The fundamental difference between the die is that its dies are sliding and are made up of four halves, so they can be adjusted to cut threads of different diameters, but of the same pitch. When placing the clamp on a section of pipe, the dies are brought to the surface and secured in the desired position. Adjustment of the relative placement of the detachable dies of the die is carried out by moving its design washer.

The threaded die already has a guide element in its design; based on this, there will be no distortion of the cut thread when using it.

A more practical type of clamp is considered to be a ratchet clamp, the design of which includes a ratcheting mechanism. Thread cutting is carried out not by rotational, but by rocking movements of the handles with simultaneous feeding of the die. The clamp is indispensable if you need to cut a thread on a pipe without removing it from the pipeline section.

Development of slicing

The sequence of thread cutting on a pipe consists of the following steps:

1. Clean the desired section of the pipe from rust, other irregularities and paint stains on the outer diameter of the pipe.
2. Liberally lubricate the required section of the pipe with machine oil or sulforesol, due to which the load on the handle when cutting will be much less. The same can be done with respect to the die/dies.
3. Securely secure the pipe in a vice. Along with this, the end of the pipe protruding for threading should not be more than 5–8 of its diameters; otherwise, cutting accuracy is not guaranteed. Dies with a guide bushing or die do not require such restrictions.
4. The pipe is prepared for cutting by using a file to obtain a lead-in cone at the end with a height of at least half the height of the die. At this point, a running section of thread is formed; if this is critical, then it can then be removed with a hacksaw.
5. A die or die is inserted, and by vigorously rotating the knob, the desired threaded section is obtained. Don’t forget that the length of the cut section of the thread should be a couple of turns more than required. To be sure, you can run the die over the cut area a couple of times.

So, if you follow the recommendations and instructions proposed in the article, you will be able to quickly and properly cut threads on a pipe. Do you have any questions on the topic? Then ask questions by writing a comment on the article.