Any repair or replacement of an existing pipeline involves connection to the highway. Welding is only suitable for metal pipes, while this method cannot be used to connect them to plastic products. in addition, shut-off valves are used during installation, which is fastened with a threaded connection. To create it you need to know, how to cut a thread on a pipe and by means of what devices.
There are several types of tools for threading
Threading. Necessary concepts
This process is the processing of the rod or hole with a special tool for threading pipes in order to obtain external or internal alternate protrusions-turns and spiral grooves.
The main characteristics of the thread are:
- step. This is the distance between the vertices or bases of adjacent turns;
- profile. The cross section of the coil may be trapezoidal, triangular, rectangular, etc.. Only a triangular profile is used in the details of sanitary systems;
- profile angle. It is formed by intersecting sides (side faces) turns;
- depth. This is the distance from the top to the base of the thread;
- external, middle and inner diameters.
The outer is equal to the distance between the points of the two opposite sides of the thread. Average diameter ? this is the distance between the top and bottom of the profiles, which are on opposite sides of the part. The inner is the distance between opposite depressions.
Each thread has its own technical characteristics
Types of threads on pipes
Although the procedure for cutting a thread on a water pipe can not be called complicated, listening to some tips will not be superfluous. Ability to distinguish left and right threads, and an inch from the metric will not hurt either.
With the left-hand thread on the bolt, the nut is screwed counterclockwise. If the right thread, the nut is turned on the bolt clockwise.
Metric thread is characterized by, what:
- geometric dimensions of parts are measured in millimeters;
- profile type - equilateral triangle;
- has a smaller step.
Features of an inch carving are:
- unit of measurement of geometric dimensions of parts - inches;
- has the form of a profile of an isosceles triangle with an angle at the vertex equal 55 degrees;
- has a bigger step. This feature means, that the profile of the inch thread is larger, and the bond strength is higher.
All types of threads are used in certain cases. But it is worth noting, that rights are found at literally every turn, but the left - much less often.
To properly cut the thread, you need to know, how they differ from each other
Tools and rules for threading pipes
Of course, to perform this procedure, without a tool for threading pipes can not do. In trade it is usually called a pipe thread-cutting set.
Useful Information! The set may include a tool with an unusual name for the club. It resembles a die for cutting threads on pipes, but contains only its main functional part - a round frame in the form of a short cylinder, made of tool steel and equipped with strong cutters.
Except dice or benches, the set includes a holder (with or without a rattle), as well as a number of other additional tools, such, like ticks, clamp, etc.. d.
Requirements for the process of threading pipes by hand are formulated as follows:
- mandatory pipe preparation. Dirt must be removed from the place of the future thread, rust and a layer of paint. The surface should be cleaned to metal;
- the process of cutting threads on pipes must be accompanied by lubrication of their working surfaces of tool cutters - dies or benches. Lubricant is used for this purpose, which is a special liquid. It is applied as before, and in the process of threading the pipe;
- at the end of the product you must first remove the outer chamfer;
- work should be carried out only with a sharp and serviceable tool for threading on water pipes.
In addition to technology, it is important to know the intricacies of choosing a tool.
Threading, technology must be strictly adhered to
Threading tools are not only the above-mentioned dies and benches, but also taps. With the help of the latter, an internal thread is created by cutting chipboard grooves. But there is one nuance. A set of two taps must be used to cut the thread on the pipe, differing in the depth of eruption:
- for rough work - №1;
- for finishing work - №2.
A die for cutting threads on pipes happens:
- round;
- extensible;
- split;
- integral.
Another tool - a loop - has a guide in its design. It is used to center the cylinder with cutters on the pipe.
However, some knowledge, than the thread on a water pipe is cut, not enough. It is necessary to find out the requirements of the GOST for the size of the pipe thread, and already in accordance with its steps and diameter to select a set of threading tools. These data are presented in the table below.
Table 1
Thread pitch | Thread diameter, mm | The size of the pipe thread, inches | |||
mm | Thread on 1 inch | Internal | External | ||
2,309 | 11,0 | 84,930 | 87,887 | Three | |
2,309 | 11,0 | 72,230 | 75,187 | 2 1/2 | |
2,309 | 11,0 | 56,659 | 59,616 | Two | |
2.309 | 11,0 | 44,847 | 47,805 | 1 1/2 | |
2,309 | 11.0 | 38,954 | 41,912 | 1 1/4 | |
2,309 | 11,0 | 30,293 | 33,250 | One | |
1,814 | 14,0 | 24,119 | 26,442 | 3/4 | |
1,814 | 14,0 | 18,632 | 20,956 | 1/2 |
Stages of cutting a pipe thread by hand
As mentioned above, this operation is performed using a die, bench or tap. The choice of a set for threading pipes depends on many factors. But, first of all, from that, which thread needs to be created external or internal. For more specifics, consider, how to cut a thread on a stainless steel pipe by hand with a die.
Cut off part of the stainless steel pipe, on which there is an old carving. It is inexpedient to be engaged in its restoration, since it will be impossible to achieve complete tightness of the connection and, so, leaks will occur in this place. Performing this operation manually, pay special attention to the cut. It must be strictly perpendicular to the longitudinal axis of the pipe.
Importantly! The segment of the pipeline with signs of corrosion is also subject to removal.
To facilitate the winding of the die, remove the chamfer from the end of the pipe. To ensure better glide, lubricate the place of the future thread with oil. Next, start the actual cutting of the pipe thread. After a number of turns, the die should be rolled in the opposite direction.
With the help of a die it is easy to cut the external thread
When you have finished cutting the pipe thread, remove the metal sawdust from the newly created joint.. To verify the correctness of the work, screw the object to be installed on the pipe. This way you will find out the correctness of using the selected die for cutting threads on pipes, as well as a sufficient number of turns. If the test is successful, seal the connection and start installing the plumbing system.
Advantages of the bench
Some features of this tool, used for threading pipes, that were mentioned above. But ease of use ? this is not the only advantage of such a set. So, example, knowing in practice, how to cut a thread on a pipe with a die, you will easily cope with this task, using a loop. Among other advantages it is necessary to allocate purity of the received carving, simplicity of a bench design, the ability to quickly replace die cutters and light weight.
The following factor deserves special attention. Cheap tool steel is used to make the die. But only cutters should have increased strength, actually do the main work! The lack of expensive functional parts causes a decrease in the cost of a set of benches and, in accordance, reduces the cost of the process of cutting threads on stainless steel pipes. Therefore, home builders, who know how to count money, prefer this tool.
The use of a bench will significantly facilitate the task of cutting threads
These products are sold with a set of dies for cutting threads on pipes with a diameter 50, 38, 32, 25, 20 and 15 mm. Each of them is denoted by a number 1, 2, 3, or 4. All slots on the body of the bench also have numbers, corresponding to die cutters, with the help of which the thread on the pipe will be cut. To increase the efficiency of work in hard-to-reach places together with the club, it is recommended to buy special equipment.
Today on the market you can find such a tool with electric and manual drive. Therefore, a question may arise, than the thread on the pipe is cut more efficiently.
Useful Information! Benches are sold in specialized as stationary, and online stores. The latter are very convenient, as it is possible to become the owner of the corresponding set for cutting of a carving on pipes, without leaving the confines of his home.
Professional locksmiths, who already know for sure, how to cut a thread on a pipe, prefer electric benches. But there are such devices. Therefore if it is planned to carry out one-time cutting of a carving on a pipe,it is more profitable to buy a set of tools with a manual drive.