How to cut a thread with a die: types of tools, principles of cutting | mk-soyuz.rf
Threaded connections are used to fasten metal parts. This is due to the reliability of the coupling and the ease of twisting individual elements. Special tools are used to create threaded connections. A novice master needs to know how to cut a thread with a die.
What is a die?
A die is a tool for creating threads on the outer surface of cylindrical workpieces. Uniform twisted grooves appear on the machined side, onto which the connecting part is screwed. Smooth threads are obtained thanks to the complex arrangement of edges located on the inside of the tool. As the tool rotates, the sharp edges create uniform turns.
The design of the die is cylindrical in shape with precise placement of cutters on the inside. The diameter varies depending on the size of the workpieces being processed. The equipment has holes that are needed to secure the knob. With its help, force is transmitted to the equipment.
Specifications
The tool for creating threaded connections has a number of technical characteristics:
- Diameter of equipment.
- The material from which it is made.
- Thread pitch. It is designated by the letter “M”, followed by millimeters.
The working parts of the die are made of high-speed steel.
Purpose
The die is designed for creating external threads on pipes and cylindrical metal parts. Such tools can be used for manual processing of parts or installed on industrial equipment. A special saw is used for cutting threads.
Classification
In construction stores you can see different types of tools. Equipment is classified according to the following criteria:
- body design,
- a method for creating coils on the surface of a workpiece,
- equipment form.
If we talk about classification by form, we can distinguish the following types of instruments:
- round dies,
- tubular equipment,
- square dies,
- equipment in the shape of a polyhedron.
Speaking about the design of the tool, we can distinguish the following groups:
- One-piece equipment. The most popular option. It is a round cast form whose body cannot be disassembled. It has several holes for securing the knob. This type of tool gained popularity due to its ease of use, reliability, and durability. The sharpening of the cutters lasts for a long time.
- Cutting tools. Special devices that have certain design features. Thanks to this, the process of creating threads is simplified.
- Sliding structures. They are modern devices that can be expanded to the required diameter. These are expensive models.
Another classification concerns the purpose of the equipment. There are 3 groups:
- production of round threads,
- creating a cylindrical threaded connection,
- production of conical shape.
Devices are made in factories in compliance with a number of standards specified in government documents GOSTs.
Rules for cutting threads using dies
Cutting threads with a die manually requires compliance with certain rules. Knowing the principles of working with the tool, you can create a high-quality, durable connection. In order to work with the device for creating a threaded connection, you need to use a die holder. Work rules:
- Determine the exact diameter of the pipe, select equipment according to the markings indicated on its surface.
- Prepare the workpiece. Remove the chamfer using a file. The chamfer angle should be no more than 45 degrees. A larger angle will make the connection poor quality.
- To make the cutting edges last longer, you need to use lubricant during operation. It could be motor oil. They lubricate cutting parts and workpieces.
- The die holder must be turned clockwise two turns, then make 1 turn in the opposite direction. When the cutting edges move backward, the resulting chips come out and do not become clogged in the finished turns. It is important to hold the tool with the crank strictly vertically so that the threads are straight.
- After creating the first 3-4 turns, you need to reduce the stroke of the die in the opposite direction. It will be enough to make two turns clockwise and half a turn counterclockwise. You cannot continue working if the equipment is overheated; you need to take breaks.
When the required number of turns has been made, the quality of the finished connection needs to be checked. To do this, you need to take a nut of the selected diameter and try to screw it onto the pipe. The first times the nut will be screwed on slowly, with difficulty. Gradually these problems will disappear. Uneven threads can cause damage to the connection during operation.
Dies are used to create external threads on cylindrical parts. It is important to choose the right diameter and know the rules for working with equipment. The inside of the round parts is processed using swords. The equipment is suitable for both manual work and industrial equipment.
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How to properly cut a thread with a die
Threading is the processing of a hole or rod element in a workpiece, in which a special tool is used to obtain a cut inside or outside. The cutting contains turns, protrusions, and alternating grooves in the shape of a spiral.
Cutting is carried out on pipe products, nuts, bolts, which are used in, for example, water pipes and various parts of equipment. If you are installing a pipeline using products without threaded connections, you need to learn how to cut pipe threads.
According to GOST, it is characterized by the following indicators:
- step - the distance between the bases or vertices of adjacent curls;
- depth - the distance from the base to the top;
- profile - a cross-sectional view of a coil located transversely;
- profile angle - formed by the lateral parts of the turns that intersect;
- internal/central/external diameter – the distance between the bases of the opposite sides/base and the top of the opposite side/points of 2 threaded sides located in opposite areas.
Types of cutting
External threading on bolt, rod and screw elements is created using dies and can:
- have a prism shape;
- have a circle shape;
- be retractable;
- be monolithic.
Prism-shaped cuttings have 2 identical parts, fixed in the die in the form of a frame with handles. On the 2 outer sections there are recesses intended for clamping protrusions.
Sliding dies are placed in the die so that the numbers on the die elements are placed on the opposite side of the numbers on the frame. Fixation is carried out with a special screw. A metal plate block is placed between the die and the stop screw to prevent deformation.
The circle-shaped die is fixed in the collar holder with 2 or 4 stop screws. Using a sliding die, it is possible to manually create a thread on a product, even if there are small deviations in the rod radius.
How to cut threads on the inside of a pipe? This is done using pipe thread taps inserted into the crank part. The tap has a tapping part designed to create threads on the pipe; calibration, through which it is possible to calibrate and cut a hole; a shank with a square-shaped head that allows you to hold the tap in the crank part.
Basic thread positions
When connecting gas pipes to a water supply, cylindrical pipe threads are rolled or cut. The end parts of the pipes are combined with special elements. The last 2 curls of the cylindrical cut are called runaway. The run-out allows you to fix the coupling element on the pipe product. This ensures the sealing of the connection with the seal.
To disconnect connected heating pipes, for example, without cutting, you need to use a squeegee. It contains a lock nut, a coupling element, and a long thread. It has such a length that it is possible to easily screw on the coupling part, the locknut.
In order to save material, gas supply and other complexes use products with thin walls. They are knurled. The thickness of the walls should be greater than when creating threads on a water pipe.
Pipe clamps
On small-sized products, external threads are created with your own hands using pipe clamps. The product is placed in a clamping tool, and the end section is cleaned of scale. After this, the area that is being cut is lubricated with drying oil or sulfofresol.
They put a special object on the pipe with their own hands - a clamp, it has special dies. Using a mallet, lightly hit the washers on the handle so that the direction dies move closer to the pipe. Next, they are secured with stopper bolts. The cutting dies are installed, while resting on the washer mark.
Then the tool is rotated, simultaneously pressing on it.
In the body part of the die, on one side there are 4 holes for the cutting die, on the second - 3 holes for the direction die. The dies are moved away, and the washers are brought closer to each other. They are fixed with ring clamps on the body. In the planes that are adjacent to the body, there are recesses of washers in the shape of a spiral.
They contain pin components. If you turn the washer, the pin components will slide along the recesses, the dies will begin to approach each other (during a left turn) and move away (during a right turn). When they occupy the optimal position, the washer is fixed using the clamp bolts.
Dies are produced, in accordance with GOST, with 2 sets of special dies: for cutting on products with a radius of 0.75-1 cm and 1.25-2.5 cm.
The dies use radial single-sided/double-sided dies. One set contains four items. Each of them is marked with dimensional data and an identification number (from one to four). Special numbers are available for any hole on the body of the screw. The product contains replaceable bushings for any diameter. They are located in the guide flange element and are fixed with a screw part. It is attached to the body part.
Pipe clamps provide the opportunity to obtain clean threads and also make the product stronger. The downside is that they need to be carefully looked after. In addition, the clamps weigh a lot.
If a special tool is used to cut threads on pipes, and the thread has a diameter of 5 cm, it is necessary to move the direction dies by rotating them one hundred and eighty degrees, that is, towards the inside of the die with the shorter section.
Klupp Mayevsky
How to properly cut threads on a pipe? For such a procedure, Mayevsky's clamp is often used. It has split dies containing a couple of elements. Any set of dies is designed for a certain pipe radius. The dies, according to the number indicated on them, are placed in the housing connector with screw elements according to the marks contained on the product. A stop cover is placed on them, which is secured with screw elements.
Mayevsky's clumps are structurally simple, easy to care for, and weigh little. In addition, the dies can be quickly replaced.
Ratchet clamps
How to cut threads on a pipe, besides the above methods? It is possible to use a ratchet clamp. It is designed to create threads with a diameter of 2.5/2/1.5 cm on products, for example, stainless steel. A head is fixed in its body part, which is equipped with replaceable dies. There is a ratchet wheel at the bottom. When turned, it ensures rotation of the die head.
What tool is used for cutting internal threads?
There are 2 ratchets in the clamp housing. The die head rotates using the handle. Cutting is carried out using a rolling motion, it is performed by the handle when the wheel is running.
Upon completion of cutting, a ratchet is launched, clinging to the teeth and driving the die-circle. Using a die, it is possible to make carvings in those areas in which the use of ordinary tools is ineffective. It is especially useful during repairs.
To create a thread on a product, it is fixed in a clamping device so that the protrusion being processed is small. The longitudinal protrusion may be subject to deflection when cutting. The end part of the treated area should be placed at an angle of ninety degrees relative to the pipe axis.
The tool is mounted on the product with directional rings/dies. The cutting dies should extend a couple of turns onto the tubular product. The pipe threads are lubricated with oil fluid. This is required to cool and clean the dies. Before you begin the procedure, check that you have installed the die correctly.
Its number must be the same as the number of the housing connector.
To cut, the tool is twisted and moved to the front. At the end of processing the product, the clamps are disassembled, cleaned of dirt and metal filings, and lubricated with mineral lubricant. Every week you need to clean the tool from dried grease.
Source: http://ooo-asteko.ru/kak-pravilno-narezat-rezbu-plashkoy/
Thread cutting tool: features of manual and automated processing
Often, in home and industrial conditions, a question may arise regarding the shaping of the thread. Without this, it will not be possible to produce fastening steel, install plumbing communications or piping, or carry out repairs. To create threads in solid metal rods and pipes, a die or, as it is also called, a die, is used. It is this tool that will be discussed further.
Types of dies
Dies (dies) for thread cutting are classified as follows:
- According to the properties of the cut part, namely the pitch and diameter of the thread;
- According to the method of thread formation (manual and machine);
- By type of thread profile on the finished product;
- According to the material used to create the equipment.
| Very often, taps are confused with another tool for creating internal threads - taps. We have already written about the features of this device and its varieties in our material. |
A thread holder is very often used together with a die holder, which is a special equipment where the thread-forming device is fixed. Depending on the design of the lever, the appearance of this instrument will also change.
For example, flat-shaped die holders are found in machine forming of threaded profiles. In the case of manual thread cutting, the die holder is equipped with 3-4 goujons holding the die and a special handle.
The former are evenly distributed along the arc of the landing surface.
Many companies involved in the manufacture of dies create identical outer surfaces for adjacent groups of threads, which makes die holders more universal. These models include M12 and M10. Ledgers, with the help of which it is possible to achieve threads with different pitches, but of equal diameter, are also unified according to the seats.
As for the marking of the dies, it will necessarily include a letter designation - M (metric) or D (inch). Lerks equipped with left-hand threads are much less common. As a rule, they are used in heating radiators, in mountings for devices for tying ropes and cargo cables. In this case, the designation LH is added to the marking.
Ledgers used to form threads on pipes are marked with an additional Latin letter G. They differ in the shape of the thread-forming part, which can have a conical profile, and are mostly used for cutting threads on pipes, for example, in adapters or bends.
The characteristics and parameters of domestic lekars during production are regulated by GOST 9740.
Dies for manual shaping
In the case of manual threading, the die itself rotates, and the workpiece, be it a pipe or a rod, remains motionless. At the same time, there is no peripheral speed, due to which the thread cutting tools hardly heat up very much. To reduce the cutting effort and wear of the thread-forming part, the working platform is lubricated. It is only necessary to additionally lubricate the inner surface of the die if the diameter of the thread and the diameter of the workpiece are very different.
The diameters of the initial workpiece to create a full threaded profile are presented in the table below.
| Diameter of cut thread | M6 | M8 | M10 | M12 | M16 | M20 |
| Workpiece diameter, mm | 5,8-5,95 | 7,75-7,90 | 9,7-9,95 | 11,8-11,95 | 15,8-15,95 | 19,8-19,95 |
The dimensions presented in the table can be used to calculate the diameter of the workpiece before cutting threads on automatic machines with flat dies.
An important point when choosing a lecher is the material of the tool. During the threading process, the force gradually increases, dropping sharply at the end - thus predetermining the increased viscosity of the die material. Otherwise, the threaded profile would be severely chipped.
Taking this into account, the best choice is considered to be levers made of tool alloy steel grade 9XC and X12F1 with a hardness of 59-61HRC.
When using alloy and heat-resistant steels for threading, it is best to use a die made of high-speed steel R9K6 or R6M5 with a hardness rating of 60-63HRC.
It is important to note that the use of these blades becomes justified only when large quantities of workpieces are processed, since the cost of the tool is not the lowest.
In domestic conditions, it is allowed to use a die for cutting threads made of tool carbon steel U12 or U10.
Products from foreign companies CM Tools (Finland) and UFC (Italy) have received good reviews.
Among the highest quality manufacturers engaged in the production of tooling, it is worth highlighting enterprises from Lvov (Ukraine), Samara, Izhevsk, Minsk (Belarus), Bryansk, Chelyabinsk, Orsha, Vladivostok and Nizhny Novgorod.
Tools for machine thread cutting
In comparison with the manual method, the workpiece in machine forming performs screw movements, and the die reciprocates. In this case, the levers are divided into fixed ones, when they are mounted directly on the table, and movable ones, which are fixed in the slider of the machine.
In the case of stationary lecterns, the work area is represented by 3 parts:
- Calibrating, where the main parameters of the thread are adjusted, after which a smooth exit of the product from the thread formation area occurs;
- Profiling, where thread rolling is performed;
- The fence, where the workpiece capture begins.
This method does not allow the development of strong vibrations, which are inevitable due to the peculiarities of the device’s operation: the presence of idle speed, when, when gripping a new workpiece, the die with the slide returns to its original position, and high productivity (about 400 rpm).
The movable die has a less complex design. The length of its receiving area in comparison with the diameter of the workpiece reaches about 30-35 percent. The profile rises at an angle of 4-7 degrees to the desired level of profiling. During the reverse stroke of the slider, accidental capture of the knurled workpiece is eliminated due to the fact that the length of the movable lever is greater.
Using a machine die, you can easily cut both ordinary threads and more complex profiles, for example, threads for screws and self-tapping screws, as well as grease nipple heads. To do this, a special ridge is created on the form-forming section of the die, where the required sharpening of the end of the fixed element is created in the grooves.
Compared to hand-made lehrs, machine ones should have a slightly lower hardness, around 56-58HRC, which will eliminate unwanted cracks after long-term use of the tool.
As a rule, dies for machine thread cutting are produced by enterprises engaged in the production of thread rolling equipment. Among the most notable companies are the Belgian Malmedie, the Japanese Sakamura and the Italian Sacma and Sima.
In addition to the listed manufacturers, there are products on the market today from Taiwan and China, which are lower in cost, but their mechanical properties and performance characteristics raise a number of questions!
Source: https://ProStrouky.ru/instrumenty-i-oborudovanie/plashka-dlya-narezki-rezby-klassifikaciya-instrumenta-nyuansy-ruchnoj-i-mashinnoj-obrabotki.html
How to cut external threads. Thread cutting on pipes and fittings. Die. Klupp
How to cut external threads. Thread cutting on pipes and fittings. Die. Klupp. 4.46/5 (89.23%) lost 13
External threads are cut using round or sliding dies, as well as screw boards. Thread cutting can be done either on machines or manually.
Cutting threads with round dies.
Round dies (lerks) are a disk with a cut hole. To remove chips and form feathers with cutting edges (Fig. 1), several chip holes are made in the die. The dies (lerks) are inserted into the lerk holder and clamped with screws (Fig. 2).
Rice. 1. Round split die (cutting die).
Rice . 2 . Card holder:
1 - frame; 2 - handle; 3 - clamping screw .
The diameter of the cut rod is taken to be slightly smaller than the outer diameter of the thread and is sawed down in a cone shape to fit the hole. The selection of rods for cutting metric or inch threads is given in table. 1:
Table 1. Diameter of rods for threaded bolts .
| Metric thread | Inch thread | ||
| Outer diameter in mm | Rod diameter in mm | Outer diameter in inches | Rod diameter in mm |
| 5 | 4,89 | 1/4 | 6,19 |
| 6 | 5,86 | 5/6 | 7,7 |
| 8 | 7,83 | 3/8 | 9,3 |
| 10 | 9,8 | 7/16 | 10,8 |
| 12 | 11,7 | 1/2 | 12,4 |
| 14 | 13,7 | 5/8 | 15,6 |
| 16 | 15,7 | 3/4 | 18,7 |
| 20 | 19,6 | 7/8 | 21,8 |
| 22 | 21,6 | 1 | 25 |
| 24 | 23,6 | 1 1/4 | 31,3 |
| 27 | 26,6 | 1 1/2 | 37,6 |
| 30 | 29,5 | 1 3/4 | 43,8 |
| 36 | 35,4 | 2 | 50 |
Sliding dies (Fig. 3, a) consist of two prismatic halves with a cut hole. In the middle part of the hole the dies make a groove, which forms the cutting edges.
Rice . 3 . Sliding dies and crackers:
a - die; b - cracker.
Clamp for thread cutting.
To fasten the dies, a clamp with a rectangular or oblique frame is used (Fig. 4). The prismatic protrusions of the die fit into the grooves of the dies, and the dies are pressed against the sides with bolts.
Rice . 4 . Klupp (oblique) :
1 - frame; 2 - handle; 3 - clamping screw .
To avoid direct pressure of the bolt on the dies, a so-called cracker (see Fig. 3, b), shaped like a die, is installed between the dies and the bolt.
Die thread cutting technology.
Cutting with prismatic dies is somewhat different from cutting with lerks. When cutting into dies, the rods are not sawed into a cone, but the dies are moved apart. Then they are clamped on a rod, the end of which should coincide with the upper plane of the dies. By turning the die to the right and slightly to the left, threads are cut. The position of the holder and clamp is set strictly perpendicular to the rod being cut, otherwise the thread will be oblique and one-sided.
Cooling and lubrication during thread cutting.
When cutting threads with taps and dies, it is necessary to use lubricant. As a lubricant, you can use a regular emulsion, dissolving one part of the emulsion to one hundred and sixty parts of water. In addition, you can use: for cast iron - lard and kerosene ; for steel and brass - boiled and rapeseed oil and lard ; for red copper - lard and turpentine ; for aluminum - kerosene .
It is not recommended to use machine and mineral oils when cutting threads, since they, while increasing the resistance to cutting, do not produce clean holes and lead to rapid wear of taps and dies.
Screw boards.
In order to cut threads on screws with diameters up to 6 mm, screw boards are used. The screw boards have several cut holes of different diameters with grooves for chips, two for each hole.
Thread cutting with dies is performed in the same way as tapping. The rod is firmly clamped in a vice, lubricated with oil, and then a clamp with dies is put on the rod, clamped with a screw and rotated a full turn in one direction and half a turn in the other. If the rod is thicker than required, it must be filed with a file.
Bolt threads are measured using ring thread gauges or a thread gauge.
Thread cutting on pipes and fittings.
Pipes and fittings (connecting parts for pipes) are cut with a special tool using fixtures.
Jig for cutting threads on pipes.
The threads on pipes are cut with a special die (Fig. 5). The device for cutting pipes differs from conventional clamps. Four steel combs fit into the slots of its clip. By turning the top handle they can be brought closer or apart. Therefore, one die can cut pipes of various diameters. In addition, the die has guides that are adjusted by the lower handle. The guides ensure the correct position of the die on the pipe when cutting.
Rice. 5. Jig for cutting pipes.
When cutting, pipes are secured with a special pipe clamp. The clamp consists of a frame into which crackers with cutouts for pipes of various diameters are placed.
Tapping threads on fittings is done in the same way as tapping holes. Only the fitting tap has pipe threads, and the pipe tap kit includes two taps.
Source: https://mechanicinfo.ru/kak-narezat-naruzhnuyu-rezbu-narezka-rezby-na-trubax-i-fitingax-plashka-klupp/
Is it possible to cut a thread with a die and how to do it?
Threaded connections are used to fasten metal parts. This is due to the reliability of the coupling and the ease of twisting individual elements. Special tools are used to create threaded connections. A novice master needs to know how to cut a thread with a die.
Thread cutting die
Navy
A die , or popularly a lerka, is a thread-cutting tool for cutting external threads manually or by machine (on a machine) [1] [2].
Previously, the name die was used in relation to a typesetting and adjustable thread-cutting tool, preferably of larger diameters [ source not specified 426 days ].
The die has a non-separable shape and has a threaded hole with grooves; the cut thread is more accurate than that of dies. Currently, the division into dies and lerks has ceased to exist.
Dies are designed for cutting or calibrating external threads in one pass. The most common dies are for cutting threads with a diameter of up to 52 mm. The die is a hardened nut with axial holes that form cutting edges. As a rule, 3-6 chip holes are made on the dies to remove chips.
The thickness of the die is 8-10 turns. The cutting part of the die is made in the form of an internal cone. The length of the fence part is 2-3 turns. Dies are made from alloy steels (9ХС, ХВСГФ), high-speed steels (Р18, Р6М5, Р6М5К5, Р6М5К8), and more recently from hard alloys.
They are marked with the designation and degree of accuracy of the thread being cut, and the grade of steel (9ХС is not indicated).
Types of dies : solid , split and sliding (clump). Depending on the shape of the outer surface, dies are round , square , hexagonal , or prismatic .
Round dies - secured for work in gates with locking screws or secured in thread-cutting chucks. For this purpose, there are conical recesses and an angular groove on the outer cylinder of the die. The latter allows you to cut the die with a grinding wheel along the bridge and partially adjust the diameter. For round split dies, knobs with five screws are used, with the help of which the diameter of the thread being cut is adjusted.
Solid dies - due to their high rigidity, they make it possible to obtain high-quality threads (metric, conical), but have low wear resistance.
Sliding dies - installed in dies that have special guides for this purpose. The die consists of two parts, secured in the die frame with a block and a screw. This screw adjusts the diameter of the thread being cut. The die comes with a set of dies, which allows you to make threads of different sizes.
Split dies - can spring a little, changing the diameter of the thread being cut by 0.1-0.3 mm. Due to their low rigidity, split dies do not produce clean and accurate threads.
It is difficult to imagine a mechanical working tool or functional part that would not work through the use of threaded connections. Cars, hand tools, household appliances, plumbing - this is just a small list of equipment that would not be able to function without modern threads.
Set of dies for thread cutting
It is not surprising that so often a person has to sharpen the threads on parts himself. Fortunately, this is quite easy to do. In your work you will need a small set of basic tools, taps and dies.
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So how to do thread cutting correctly? Let's figure it out now.
Tool selection
Let us note in advance that threads can be cut in different ways. You can work either manually or by machine. In the first case, as we noted above, you need to have a set of tools with you for creating threads, in the second, the work is carried out on a lathe.
Manual threading is recommended if your task is to machine only a few parts. For example, when assembling plumbing equipment, creating household pipelines, etc.
Processing parts on a lathe involves performing large-scale tasks. A person with experience with this type of equipment is able to cut threads on an industrial scale, up to a hundred parts per hour, and sometimes more. However, you are unlikely to need such performance.
Most often, a set of hand tools covers all the household needs of home craftsmen. With their help, you will also be able to cut threads correctly and efficiently, but it will only take more time and effort.
The set of equipment mentioned above is mainly represented by taps and dies, as well as various additional parts.
Features of taps
Taps are cone-shaped or cylindrical parts that are designed for cutting internal threads. In particular, they are used to make threads on pipes, nuts, small washers, various kinds of clamps and even flanges.
The taps are quite convenient to use. They consist of a working and a rear part. The working part has a unique shape and diameter. On its edges there are special incisors or teeth with a certain pitch. The teeth, when rotated, cut the metal in parallel with the removal of chips.
The back side is made in a certain shape, which makes it easier to fix the tap on the working tool.
A variety of taps for household use
Taps with the ability to cut threads without forming chips are also used, but much less often, because they are more expensive.
Roughers make the first pass, remove most of the chips and form rough grooves for the threads. This is not a full carving yet, but the preparation has already been completed.
Semi-draft models are extremely rare. They are intended for finishing rough grooves, cleaning them and forming a workpiece for a clean thread. Semi-rough taps are used primarily in the manufacture of complex parts.
The last sample, a finishing tap, forms a ready-to-use thread of precise dimensions and shape.
According to the type of actions performed, taps are divided into:
Note that taps, as well as dies, can cut threads of different sizes, directions and shapes. It all depends on the chosen equipment model.
Features of dies
A die is a cutting tool that is used when making external threads. The simplest example of an external thread is a bolt. While an example of an internal thread is a nut.
The dies are flat, from the outside they strongly resemble large washers or clamps for machine chucks. Only inside the die there is a cutting attachment with several rows of twisted cutters.
Tap and die, close up
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Dies can have different shapes, types of assembly and dimensions. There are both round and square models. Some options are completely solid, others can be disassembled and the cutting attachment can be replaced.
The cutting part consists of three working zones. The two zones located at the edges consist of teeth, while the inner zone is responsible for removing chips and adjusting the direction of rotation.
It is thanks to the inner zone that the dies have a self-tightening property. That is, after several rotations on the pipe, the die is fixed.
You can then rotate it without pressure, since it will tighten in the direction of the thread formation. While the taps must be rotated with force throughout the entire process.
The types of dies are essentially the same as the types of taps. If you bought a large set of tools, you will probably receive several of these parts at once.
Threading
Now that we've sorted out the tools themselves, let's move on to the question of how to use them correctly.
Almost anyone can cope with such tasks, but there are several details and nuances in the work that you should pay close attention to.
The standard stages of work differ little from each other, and it does not matter whether you use dies or taps. In any case, it is necessary:
- Prepare and assemble the instrument.
- Lubricate parts and work area.
- Perform a rough pass.
- Check the quality of the thread.
- Perform a finishing pass.
- Perform final check.
There are also nuances that we will now pay attention to.
Carving with a die
Most often, a set of dies is used when it is necessary to obtain a result in the form of a pipe thread. At least in civil engineering.
When cutting threads with a die, caution plays a major role. First, the die is selected and assembled with the die holder (popularly called a knob). Then lubricate with oil or lard, if nothing else is available.
Next it needs to be fixed. At the fixation stage, beginners very often make serious mistakes. The die is difficult to fix in the ideal position. In this case, it is necessary to start cutting using pressure, and even combining it with rotational actions.
As you understand, some skill is required here.
Mounting the part in a horizontal vice, as well as lightly turning the working edge, will greatly simplify the work. Turning is done with a file.
Then the work will go easier. The die is fixed onto the machined edge by turning it several tens of degrees in both directions. Then they press (it’s easier to work if the part is below the level of your belt, then it’s easier to concentrate the pressure from your own body) and rotate in the working direction.
Thread cutting tool set
The first 2-3 turns must be done with pressure from top to bottom, then the die is tightened on its own, and you only need to rotate the knob.
Rotation is performed with translational movements. Every few revolutions in the working direction, alternate with a reverse rotation of 0.5-1 revolutions, for better turning of the thread.
Thus performs a rough pass. The finishing pass should not cause any problems for you, since the part is already ready for processing, and the process there is identical
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The nuances of working with taps
They work with taps according to the same scheme. The tool set also includes roughing and finishing taps. They also need to be fixed on the holder, only here it is not a knob that is used, but a kind of vice that comes with the kit.
The main difference when cutting threads with this tool is the need to apply forced pressure throughout the entire time.
As a result, the process becomes more labor-intensive. It is correct to remove the chips from the tap yourself from time to time. Without removal, it will quickly grind down the teeth and damage the part. It is also advisable to cool the tap.
Due to pressure, rotation and interaction with chips, it heats up quickly. Industrial oil is ideal for such tasks.
- How to cut a thread with a die
- How to cut threads on a pipe
- How to turn on a lathe
- - detail;
- - die;
- - knob;
- - machine oil.
Selecting a workpiece for thread cutting
The diameter of the threading rod or hole is not equal to the nominal value of the finished product. When cutting external threads, select a rod having a diameter several hundredths of a millimeter smaller than the thickness of the finished product.
This is due to the fact that when removing chips, the metal is partially squeezed out, completely filling the threaded profile of the die. For cutting internal threads, the hole is also made with a small allowance to the smaller side.
The exact diameters of workpieces for cutting metric threads are specified in GOST 19257-73.
If drills of the appropriate size are used to drill holes with an inaccurate diameter, then finding a rod suitable for cutting external threads is quite problematic. This problem can be solved by preliminary grinding of a rod of standard thickness. To do this, the product is clamped into a drill chuck and treated with sandpaper evenly along its entire length, periodically taking measurements with a caliper.
External thread cutting
Before cutting a thread on a rod, it is necessary to mark the depth of the cut and clamp it vertically in a vice. The surface should be generously lubricated with machine oil or lithol. A die of the appropriate size is installed in the holder. You should start cutting threads with the starting side of the die.
It has gradually increasing depth of cutting edges, while on the back side of the die these edges are completely reduced in one and a half turns. The die must be put on the rod and cut until increased metal resistance appears. In this case, the holder handles must be strictly perpendicular to the workpiece.
After cutting, the die must be returned a third of a turn, after which full thread cutting can begin by slowly turning the holder handles. The cut threads are lightly treated with fine sandpaper and cleaned with a fine wire brush.
Source: https://morflot.su/kak-pravilno-narezat-rezbu-plashkoj-vruchnuju/amp/
How to cut a thread with a die by hand
Threaded connections are widely used in various mechanisms and machines. Bolts, studs, screws, nuts are universal, interchangeable fasteners. However, there are times when it is necessary to cut threads by hand. A specialized tool will help you do this job efficiently.
- External thread cutting with a die
- Tapping internal threads
In mechanical engineering, there are three main systems of fastening threads: metric, inch and pipe.
Metric thread has become the most widespread. It has a triangular profile with an angle of 60˚. Its main parameters, diameter and pitch, are expressed in millimeters. Designation example: M16. This means that the thread is metric, has a diameter of 16 mm with a coarse pitch of 2.0 mm. If the step is small, then its value is indicated, for example, M16 * 1.5.
The diameters of inch and pipe threads are expressed in inches. The pitch is characterized by the number of threads per inch. The specified parameters are standardized, so it is always possible to select the necessary tool.
External thread cutting with a die
To cut external threads, you will need the following tools and materials: a die or pipe clamp, a die holder, a file, a vice, a caliper, and machine oil.
The most widespread are round dies (lerks). They are either solid or split. The diameters of solid round dies are standardized. This allows you to choose the appropriate option from a large range of sizes, for example, M10, M12, M14, M16.
A special feature of split dies is the ability to adjust the diameter of the cut thread within 0.10.25 mm. However, they have reduced rigidity, which affects the accuracy of the resulting profile.
Operating procedure
The die is installed in a die holder of a suitable size. After this, it is secured with screws. In the case of external pipe threads, die holders with a ratchet are often used. They provide convenience for working in hard-to-reach places, such as near a wall.
The thickness of the rod is chosen to be 0.10.25 mm less than the diameter of the external thread. For example, for M6 with a large pitch it is 5.805.90 mm; M8 – 7.807.90 mm; M10 – 9.759.85 mm. Measurements are taken using a caliper. The diameters of rods for cutting metric threads of average accuracy class 6g are presented in the table.
To ensure better insertion of the die, a chamfer is filed at the end of the rod. Its width should be 1 - 1.5 mm for M6 M18. The workpiece is lubricated with machine oil, which makes subsequent work easier and allows you to obtain a better surface.
The die is placed on the end of the rod so that its plane is perpendicular to the axis of the bolt being cut. Next, with slight pressure, rotate the die holder clockwise (if the thread is left-handed, then counterclockwise).
When the die cuts into the rod by one or two threads, it should be turned back half a turn for better removal of chips. After this, they again make 1-2 turns along the thread and 0.5 in the opposite direction.
Using this scheme, the bolt is cut to the required length.
The diameter of the external thread is checked with a regular nut or ring gauge. If necessary, the pitch is controlled with a thread gauge.
Tapping internal threads
To form an internal thread, the following tools and materials are required:
- hammer, center punch, drill, drill bits;
- a set of taps, a driver, a bench vice;
- machine oil.
Tapping technology
The first step is to mark the workpiece and core the center of the future hole. Select a drill corresponding to the required thread diameter. This can be done using lookup tables or approximately using the formula d = D – P. Here D is the thread diameter, P is its pitch, d is the drill diameter. For example, for M10 d = 10 – 1.5 = 8.5 mm.
Step, P| 2 | 0,4 | 1,6 |
| 3 | 0,5 | 2,5 |
| 3,5 | 0,6 | 2,9 |
| 4 | 0,7 | 3,3 |
| 5 | 0,8 | 4,2 |
| 6 | 1 | 5,0 |
| 0,75 | 5,25 | |
| 0,5 | 5,5 | |
| 8 | 1,25 | 6,8 |
| 1 | 7,0 | |
| 0,75 | 7,25 | |
| 0,5 | 7,5 | |
| 10 | 1,5 | 8,5 |
| 1,25 | 8,8 | |
| 1 | 9,0 | |
| 0,75 | 9,25 | |
| 0,5 | 9,5 | |
| 12 | 1,75 | 10,2 |
| 1,5 | 10,5 | |
| 1,25 | 10,8 | |
| 1 | 11 | |
| 0,75 | 11,25 | |
| 0,5 | 11,5 | |
| 14 | 2 | 12,0 |
| 1,5 | 12,5 | |
| 1,25 | 12,8 | |
| 1 | 13,0 | |
| 0,75 | 13,25 | |
| 0,5 | 13,5 | |
| 16 | 2 | 14,0 |
| 1,5 | 14,5 | |
| 1 | 15,0 | |
| 0,75 | 15,25 | |
| 0,5 | 15,5 | |
| 18 | 2,5 | 15,5 |
| 2 | 16,0 | |
| 1,5 | 16,5 | |
| 1 | 17,0 | |
| 0,75 | 17,25 | |
| 0,5 | 17,5 | |
| 20 | 2,5 | 17,5 |
| 22 | 2,5 | 19,5 |
| 24 | 3 | 21 |
| 27 | 3 | 24 |
| 30 | 3,5 | 26,5 |
A hole is drilled into the part to the required depth, which must exceed the length of the part being cut. Using a drill with a diameter larger than d, a chamfer is made on the edge of the hole. It serves for centering and better entry of the tap.
The cutting tool is selected based on the main parameters of the thread - diameter and pitch. As a rule, a set of two taps is used. One of them is rough, the other is finishing. The driver is selected according to the size of the square of the tail part of the taps.
The part is securely secured in a vice. The rough tap and hole are lubricated with machine oil. After this, install the tap strictly perpendicular to the surface of the part and, pressing along its axis, rotate the knob by the handles.
After cutting one or two threads, make a quarter turn in the opposite direction. This promotes chip crushing and removal and prevents tool jamming.
The work continues, carrying out alternating rotation: ½ turn forward, ¼ turn back. In this case, it is necessary to ensure that there is no skew of the tap. You should also not apply excessive force to it.
To prevent jamming, the cutting tool is periodically removed and the hole is cleared of chips.
After cutting the internal thread to the required depth, a finishing tap is installed in the hole. When it goes in the given direction, a crank is put on it and work continues. Add lubricant periodically.
The thread is checked using a plug gauge or bolt. It should screw in effortlessly and not wobble. If necessary, make an additional pass with a finishing tap.
Source: https://evroterm32.com/kak-narezat-rezbu-plashkoy-vruchnuyu/
How to cut a thread with a die by hand?
Threaded connections are widely used in various mechanisms and machines. Bolts, studs, screws, nuts are universal, interchangeable fasteners. However, there are times when it is necessary to cut threads by hand. A specialized tool will help you do this job efficiently.
- External thread cutting with a die
- Tapping internal threads
In mechanical engineering, there are three main systems of fastening threads: metric, inch and pipe.
Metric thread has become the most widespread. It has a triangular profile with an angle of 60˚. Its main parameters, diameter and pitch, are expressed in millimeters. Designation example: M16. This means that the thread is metric, has a diameter of 16 mm with a coarse pitch of 2.0 mm. If the step is small, then its value is indicated, for example, M16 * 1.5.
The diameters of inch and pipe threads are expressed in inches. The pitch is characterized by the number of threads per inch. The specified parameters are standardized, so it is always possible to select the necessary tool.
How to properly cut a thread with a die? — Metals, equipment, instructions
Currently, it is difficult to imagine carrying out metalwork work without a special thread-cutting tool.
This tool can cut threads on products made of non-ferrous metals and steel.
Taps
The internal threads on the parts are cut using taps.
Taps for cutting inch and metric threads are usually manufactured in sets of two.
Taps for inch threads (less than 2 inches) and for metric threads from 32 to 54 mm with a pitch of more than 3 mm are manufactured in sets of three pieces. Such sets include the first (rough), second (medium) and third (finishing).
There is one circular mark on the tail of the first tap, two on the tail of the second, and three on the tail of the third.
The thread size is also indicated on the tail of the tap.
When cutting threads by hand, a special driver is used for the tap.
More details about video tags at the end of the article.
How to cut a thread with a tap
At first glance, cutting a thread with a tap looks simple, but this does not mean that it will be easy the first time. Pay special attention to choosing a quality tool. A dull tap has every chance of breaking. Getting the fragment out of the hole is still a hassle.
When cutting threads, follow the rule: 1 - 2 turns forward (cutting threads) - 0.5 - 1 turn back.
When cutting threads in blind holes, chips will inevitably accumulate; it is necessary to unscrew the tap and remove metal waste from the hole and from the tap.
If the tap has been removed completely, be careful when screwing it in again or when passing the next number. It is necessary to hit the already cut thread and not cut it.
The diameter of the drilled hole must correspond to the diameter of the thread (Table 1):
| Thread diameter | Hole diameter | Thread diameter | Hole diameter |
| 1 | 0,75 | 2,6 | 2,15 |
| 1,2 | 0,95 | 3 | 2,5 |
| 1,4 | 1,15 | 3,5 | 3 |
| 1,7 | 1,35 | 4 | 3,3 |
| 2 | 1,6 | 5 | 4,1 |
| 2,3 | 1,9 | 6 | 4,9 |
| 2,5 | 2 | 8 | 6,7 |
Deviations from the specified values will lead to poor-quality threads.
And of course, don’t forget about lubricants (oil, kerosene, grease, etc.).
Dies
External threads are cut using dies.
The dies are produced as sliding (prismatic), rolling and round. Round lerks are divided into cut and solid.
Solid round blades are used for cutting metric threads on parts with a diameter from one to 76 millimeters. For cutting inch threads, dies with a diameter of 1/4 to 2 inches are used.
When manually cutting threads, the dies are clamped into a specially designed driver called a handle holder.
It is necessary to use lubricating fluids and comply with the dimensions in Table 2:
| Thread diameter | Rod diameter | Thread diameter | Rod diameter |
| 1 | 0,98 | 2,6 | 2,54 |
| 1,2 | 1,17 | 3 | 2,94 |
| 1,4 | 1,37 | 3,3 | 3,23 |
| 1,7 | 1,66 | 4 | 3,92 |
| 2 | 1,96 | 5 | 4,89 |
| 2,3 | 2,25 | 6 | 5,86 |
| 2,5 | 2,45 | 8 | 7,83 |
The process of cutting external threads is clearly presented in the video:
Pay attention to the reverse rotations (opposite to the main working stroke of the tool).
Special dies and taps
Special dies and taps are tools that are manufactured with various deviations from DIN, ISO, ANSI and other standards. Changes may affect the degree of accuracy, the length and shape of the shank, the number of threads per inch, thread pitch, diameter of the thread being cut and other parameters.
Standard tools and taps are made from HSS grade high-speed steel, as well as from improved high-speed steel with the addition of vanadium and cobalt grade HSS-E. Various wear-resistant coatings are also applied to special taps.
Thread gauge
To control the profile shape, diameter and thread pitch, special and universal tools are used.
A thread gauge is used to check the thread profile.
For precise control, special microscopes are sometimes used. The diameter of the thread can also be measured with a caliper.
Source: https://spb-metalloobrabotka.com/kak-pravilno-narezat-rezbu-plashkoy/
How to cut a thread with a die by hand video
Currently, it is difficult to imagine carrying out metalwork work without a special thread-cutting tool.
This tool can cut threads on products made of non-ferrous metals and steel.
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:
Source: http://schemy.ru/info/kak-narezat-rezbu-plashkoj-vruchnuju-video/
Manual thread cutting
- How to cut a thread with a die
- How to cut threads on a pipe
- How to turn on a lathe
- - detail;
- - die;
- - knob;
- - machine oil.
