What is the name of the tool for cutting threads on pipes?

Thread cutting. Tools, thread cutting methods

Threaded connections are very widely used in mechanical engineering, so the tool for making threads is one of the most common.

Threads are distinguished:

• according to the location of the turns - external and internal;
• in the direction of the helix - right and left;
• according to the shape of the groove profile - triangular, trapezoidal, rectangular, thrust and special;
• in the direction of the generatrix - cylindrical and conical;
• according to the size system - metric and inch.

Depending on the size of the thread, the type of production and the design of the parts, different types of thread-cutting tools are used:

• thread cutters (rod and shaped single-thread and multi-thread);
• taps (hand, machine, nut, machine, tool, master, etc.);
• round dies;
• threading heads;
• thread cutters.

1. Thread cutting tool

An axial multi-edged tool for forming and processing internal threads is called a tap, and external threads are called a die.

Hand taps are used for cutting internal threads.

The working part of the tap with length f is divided into cutting (taking) and guiding (calibrating) parts with lengths l1 and l2, respectively (Fig. 1, a). The cutters of the cutting part have main edges located on the conical surface and auxiliary edges that are part of the threaded profile (Fig. 1, b).

The guide part serves to guide the tap and self-feed by screwing in, and also serves as a reserve for regrinding. The cone angle of the cutting part depends on the angle φ, which is set equal to 5° for hand taps, 3°30′ for nut taps and 6°30′ for machine taps.

The guide part has a reverse taper to reduce friction and eliminate dangerous jamming of the tap in the hole.

Rice. 1. Structural elements (a), thread profile (b) and geometric parameters (c) of the tap

The length of the tap portion of the tap is taken to be 45 S for a rough tap, 2.55 S for a medium tap, and (1.5–2.0) S for a finishing tap, where S is the pitch of the thread being cut. Machine taps are made with a short taper equal to (1.5–2) S.

The rake angles of the taps are selected depending on the material being processed according to the following data:

• for soft steel γ = 12–15°;
• steel of medium hardness γ = 8–10°;
• hard steel γ = 5°;
• cast iron and bronze γ = 0–5°;
• light alloys γ = 25–30° (Fig. 1, c).

The tail part of the tap is designed to secure it in a driver or chuck and to transmit torque.

Hand taps are produced in sets. The kit includes three taps, which are divided according to their purpose into rough, medium and finishing. Chernovoy cuts the thread, removing up to 60% of the metal; the middle one gives more accurate threads, removing up to 30% of the metal; the third (finishing) tap performs final cutting and calibration of the thread, removing up to 10% of the metal.

For cutting pipe and small metric threads, use a set of two taps.

The taps included in the set differ from each other in thread profile and length of the intake part.

According to the design of the cutting part, two types of taps are distinguished - cylindrical and conical (Fig. 2; a, b).

Rice. 2. Formation of a cutting surface in a set of taps: a – cylindrical design, b – conical design

With a cylindrical tap design, all three tools in the set have different diameters. The finishing tap has a full thread profile. The diameter of the average tap is less than normal by 0.6 of the cutting depth, and the diameter of the rough tap is less than the thread diameter by the full cutting depth.

The length of the intake part, taking into account the distribution of thread cutting work between the three taps of the set, is set in the ratio 4:2:1. Thus, for a rough tap, the length of the intake part is 6–7 threads, for a medium tap – 3–3.5, and for a finishing tap – 1.5–2 threads.

The cylindrical design of the tap ensures that the tips of the teeth cut chips in the form of wide platforms.

With a tapered tap design, all three tools in the set have the same diameter and full thread profile with varying tap lengths.

The thread within the intake part is made conical and additionally cut along the tops of the teeth into a cone.

For conical taps, the cutting part is equal: for a rough tap - the entire length of the working part, for a medium tap - half of this length, for a finishing tap - two threads.

Tapered taps are usually used when cutting through holes. Blind holes are cut with cylindrical taps.

The rear (back) surface (Fig. 1, c) of the cutting teeth is backed up in a spiral, which allows maintaining a constant profile of the teeth after they have been sharpened.

Collars and clamps . Threading with hand taps is carried out using cranks that fit onto the square ends of the shanks.

The most common are simple double-sided knobs (Fig. 3).

Rice. 3. Double-sided driver: a, a1, a2 – holes for tap shanks

Universal gates (Fig. 4) are a frame 1 with two crackers - movable 3 and fixed 4, forming a square hole. One of the handles 2 ends with a screw for clamping the square of the tap.

Rice. 4. Universal driver: a – hole for the tap shank

Another version of the universal driver is shown in Fig. 5. This driver allows you to work with taps whose square sizes range from 5x5 to 25x25 mm.

Rice. 5. Universal wrench

Round dies are used for cutting fastening threads on bolts, screws and studs when working manually and on machines (revolving, automatic, etc.).

The round die on each tooth 2 (Fig. 6, a) has a rear 1 and front 5 surface, a back of the tooth 3 and a cutting edge 6 formed by a chip hole 4. The round die has a cutting and guide part with lengths l1 and l2, respectively (Fig. 6 , b). The length of the cutting part is equal to one and a half threads of thread, and the thickness of the die is seven to eight threads.

Rice. 6. Structural elements (a), main parts (b) and shapes of chip holes (c) of a round die

Rake angles are taken for hard materials being processed γ = 10–12°; for materials of medium hardness γ = 15–20°; for soft materials γ = 22–50°.

Dies are used (Fig. 7) solid (a), split (b) and sliding.

Rice. 7. Dies

When cutting manually, round and sliding dies are installed in special cranks and clamps.

The collars for round dies are made of a frame into the hole of which the die is placed (Fig. 8).

Rice. 8. Driver for a round die

The die is kept from turning by three locking screws (1, 2 and 3), the conical ends of which fit into recesses on the side surface of the die. The fourth screw fits into the slot of the adjustable die and secures the correct thread size.

The clamps for sliding dies (Fig. 9, a) are an oblique frame with two handles. In the central hole of the frame with dimensions A and C, sliding dies are installed and centered. Installation of the sliding dies to the required size is carried out using a pressure screw 1 acting on the movable part of the sliding dies.

Clusters for cutting threads on pipes differ from conventional ones in that four steel combs 2 fit into the slots of the clamp holder (Fig. 9, b).

Rice. 9. Dies: a – for sliding dies; b – for cutting threads on pipes

By turning the upper handle 1, you can bring the dies closer together or move apart, and thanks to this, use the same die for cutting threads on pipes of different diameters. The pipe die is equipped with guides 3, which are adjusted in the same way as the dies, by a lower handle 4. This ensures the correct position of the die on the pipe when cutting threads.

2. Technology and techniques for manual thread cutting

When cutting threads with taps and dies, part of the metal is not removed along with the chips, but is squeezed out along the cutting edges of the tool, forming a thread profile on the part. Taking this into account, the diameters of holes and threaded rods should not be made according to the nominal thread size, but slightly lower than it. For metric threads with a diameter of 6–10 mm, this difference is 0.1–0.2 mm; with a diameter of 11–18 mm – 0.12–0.24 mm; with a diameter of 20–30 mm – 0.14–0.28 mm.

The diameters of holes for the most common metric thread sizes are given in table. 1.

To form a thread entry at the end of the part, it is necessary to chamfer according to the height of the thread profile.

Table 1. Diameters of holes for cutting metric threads

Material	Metric thread diameter, mm
5	6	8	10	12	16	20	24
Steel and brass	4,2	5,0	6,7	8,4	10,1	13,8	17,3	20,7
Cast iron and bronze	4,1	4,9	6,6	8,3	10,0	13,7	17,1	20,5

A tap lubricated with grease is inserted into the drilled hole and, lightly pressing it against the part with the left hand, carefully turn the driver with the right hand until the tap grips the metal and its position in the hole becomes stable. After this, the knob is taken with both hands and rotated with the hands intercepted every half turn (Fig. 10, a).

Rice. 10. Movements when cutting threads: a – with a tap, b – with a die, c – with a die

After one to one and a half turns, the tap, shaking in a horizontal plane, is rotated in the opposite direction by about a quarter or half a turn. This is necessary so that the chips break and move out of the hole along the grooves of the tap without jamming the tap. Having finished cutting, pass it through or turn the knob in the opposite direction to unscrew the tap from the hole.

The second and third taps are lubricated with oil and inserted into the hole without a driver; Only after the tap is correctly installed on the thread, apply the driver and continue threading.

Thread cutting with dies should be done in the same way. Here, however, in addition to circular movements along arrow a (Fig. 10, b), the knob should also apply some downward pressure along arrow c. During the cutting process, it is necessary to ensure that the pressure on both handles is the same.

At the first stage of thread cutting, you should ensure the correct position of the tap and die in relation to the axes of the hole and the rod. The non-parallelism of the axes and their non-perpendicularity to the end of the part are controlled by a square and are eliminated by changing the position of the tool.

It is necessary to cut threads in small and blind holes of small diameter especially carefully, without overloading the tap and often clearing it of chips.

When cutting threads in deep holes, remove the tap from the hole for cleaning (2-3 times).

If it is necessary to obtain accurate and clean threads on rods, then cutting them should be done with roughing and finishing dies.

If thread cutting is performed with dies with sliding dies, then their compression (feed) should be done only at the beginning of the pass. After each pass along the entire length of the threaded rod, the die is driven in the opposite direction and then the dies are again tightened with a screw and the thread is again cut along the entire length of the rod to be cut until the desired thread diameter is obtained. You should not press the dies in the middle of the rod. Using sliding dies, threads are cut in several passes.

To cut pipe threads with a clamp, the pipe must be securely secured in a special pipe clamp (Fig. 10, c).

The cut end of the pipe is lubricated with oil (linseed oil), and then a die is installed at a length of no more than 2–3 threads, bringing the dies closer together so that the thread is cut to the full depth in 2–3 passes. For diameters up to 1” are limited to two passes; with diameters greater than 1”, a good thread can be obtained in only 3–4 passes. Before each repeated pass, the surface of the thread being cut and the thread of the dies must be thoroughly cleaned with a brush from chips and re-lubricated with oil.

The rotation of the clamp around the pipe is usually carried out with a rocking motion in four steps; For each step you need to turn the clamp 1/4 turn.

Threads up to 1½” in ​​diameter are cut by one mechanic; For large thread diameters, two people work together. When working in tandem, a full rotation of the die must also be done in four steps.

Source: https://extxe.com/19086/narezanie-rezby-instrumenty-sposoby-narezanija-rezby/

Pipe threading

Articles

Not a single repair or replacement of existing pipelines can be done without cutting into the main line. Previously, only welding was used for this process, which is a very labor-intensive task. In addition, not everyone knows how to use a welding machine and not everyone has one.

The welding connection method can only be used for metal pipes, but if, for example, you need to connect a steel pipe with a plastic one, it will not work. Pipe thread cutting, this information will be interesting and useful to anyone who is faced with this problem, let's talk about it.

Threaded pipe

To cut a thread on a pipe, you don’t need any special abilities, but still some useful tips will be useful. It wouldn’t hurt to be able to distinguish between inch and metric threads, and between left and right threads. In fact, there are many types of threads, but often you have to deal with triangular threads - inch or metric.

Distinctive features of inch and metric thread types:

1. Inch.
   • all parts are measured in inches;
   • has the profile of an isosceles triangle (55 degree angle at the apex);
   • has a larger pitch, which means its profile is larger and the thread is more durable.
2. Metric.
   • all details are measured in millimeters;
   • has the profile of an equilateral triangle;
   • has a smaller step.

Thread cutting on water pipes is carried out in the inch system, and fasteners - in the metric system.

The thread can be:

• right, when the nut is screwed onto the bolt clockwise;
• left, the nut is screwed onto the bolt counterclockwise.

Complete and high-quality cutting of pipe threads is obtained if the diameter of the drill or rod for preparing the hole is correctly selected.

Please note: To obtain a good thread on the rod, its diameter is set, the size of which should be slightly less than the outer diameter of the thread by 0.2 - 0.3 mm.

Table with recommended rod diameters for metric threads cut using dies.

Rod diameter (mm.)	5,7	7,8	9,7	11,7	13,8	15,8	17,8	19,7
Thread diameter (mm.)	M6	M8	M10	M12	M14	M16	M18	M20

Slicing tools

Special cutting tools are intended for the thread cutting process, and we will dwell on them in more detail.

Taps

Taps - used for internal threads, they are a tool in the form of a screw. Cutting occurs by cutting chip grooves. It is equipped with a shank, which is directly attached to the driver or machine. Taps can be of different sizes, types and numbers.

For cutting threads, a set of two taps is used, which differ in cutting depth:

• No. 1 – for rough work;
• No. 2 – for finishing work.

Taps for internal threading

Die

A die (die) is a tool for cutting threads on pipes. It is a nut with holes that form cutting edges.
Depending on the shape, the dies can be:

• round;
• sliding;
• split;
• whole.

Round dies for external threading

Klupp

Klupp is a device for cutting threads on pipes. This tool has a guide that centers the die on the pipe.
There is a clamp with an electric drive, but it is not rational to purchase it in order to use it once or several times. Therefore, a manual clamp is quite suitable for home use.

Tip: It is better to immediately purchase a kit that includes a handle, ratchet and threading heads. This set will be even cheaper than buying all the parts separately.

Tool for cutting pipe threads - manual die + set

External pipe threading

Let's consider the stages of external pipe thread cutting:

1. Armed with a grinding machine, you should cut off that part of the pipe where corrosion or old threads are found.

Advice: It is not advisable to restore the old thread; it will not be completely sealed, therefore, a pipe leak may occur in this place.

Here you need to ensure that you get a perpendicular cut; this is necessary for convenience and for screwing on the adapters. The pipe should be clamped in a vice or held with a gas wrench.

1. Then, in order to make the dies easier to screw onto the pipe, it is necessary to chamfer , that is, slightly cut off the edge of the pipe so that it becomes thinner. The place of the pipe where the thread will be should be lubricated with oil for better sliding.
2. Next, you need to switch the die holder clockwise, and we begin cutting the thread . Having made a certain number of turns, we turn the clamp in the opposite direction to free the pipe from the formed metal shavings.

Please note: It is enough to cut a thread of 1 cm in size, this width is enough, since all connecting parts of the pipe: fittings, corners have threads of the same size.

1. After this work, it is necessary to remove metal filings and oil from the threads.

Threaded pipe

In order to check that the thread is cut correctly, you need to screw what you are going to install onto the pipe. This way you can determine how well the thread is cut and whether it is long enough. After a successful check, you can seal the connections and proceed directly to the installation of sewer or water pipes.

conclusions

From the information given above, it can be stated that threading a pipe is not a complicated process and can be done at home.

The main thing is to choose the right device and all the elements for it, then the process of cutting a thread on a pipe will not take much time and you will succeed.

Source: https://o-trubah.ru/soedinenie-trub/rezbovoe/narezka-rezby-na-trube-168

Tool for cutting threads. We reveal the features of the work - Tool Master

Thread shaping in industrial and home environments is a common problem. Without such operations, it is impossible to lay plumbing communications, carry out repairs and lay pipelines, or manufacture fasteners. Dies (dies), as a tool for making carvings on pipes and solid metal rods, are an indispensable attribute of the home craftsman.

Classification of leroks

Thread cutting tools are distinguished according to the following characteristics:

According to the method of producing threads - machine or manual.

According to the materials from which this equipment is made.

According to the profile of the threaded part on the final product.

According to the characteristics of the thread being cut: its diameter and pitch.

Tools for obtaining internal threads are often called taps, but this is incorrect - such equipment is called taps.

A thread cutting tool is always used in conjunction with a die holder - equipment where the thread-forming tool is secured. The appearance of such devices is determined by the design of the lectern.

In particular, for manual thread cutting, die holders are equipped with a handle and three to four gougons that secure the blade, which are evenly distributed along the arc of the seating surface.

When machine-forming threaded profiles, the die holders have the form of a flat prism.

To universalize the designs of die holders, tool companies that produce die holders make their outer surface the same for the adjacent group of threads (for example, M10 and M12). The taps, designed to produce threads with the same diameter but different thread pitches, are also unified in their seats.

The standard marking of the lerka includes in its designation a letter that determines the type of thread - inch (D) or metric (M). Rarely, lugs with left-handed threads are also used (for example, in the seats of devices for tying cargo cables and ropes, in heating radiators, etc.). Then the Latin letters LH are added to the designation of lerki.

For trenches that form threads on pipes, the letter G is added to the designation. Such trenches can have a conical profile of the thread-forming part, and are used to produce threaded parts on pipes, in particular, on bends, adapters, etc.

The parameters and characteristics of domestically produced lechers are regulated by the requirements of GOST 9740.

Tools for manual thread cutting

When cutting threads manually, the workpiece (rod, pipe) is stationary, and the tool itself rotates. In this case, there is no peripheral sliding speed, so the thread cutting tools practically do not heat up to high temperatures.

To reduce mechanical wear of the thread-forming profile and reduce the effort, the area of ​​the workpiece required for cutting is lubricated.

If there are large differences between the diameter of the original workpiece and the diameter of the thread, it is also necessary to lubricate the inner surface of the hole.

It is believed that in order to form a full-fledged threaded profile, the diameter of the initial workpiece (for the most popular diameters) must correspond to the following values:

Diameter of cut thread M6 M8 M10 M12 M16

        M20

Diameter of the original rod (or tubular blank), mm 5.805.95 7.757.90 9.709.95 11.8011.95 15.8015.95

19,8019,95

Note. The data given in the table can also be used to determine the diameter of the initial workpiece for subsequent thread shaping on machines with flat dies.

An important element for choosing the right lecher is the material from which it is made.

The peculiarity of the thread cutting process - a gradual increase in force, with a sharp decrease towards the end of the process - determines the increased viscosity of the threading material, otherwise the thread profile will intensively chip.

Therefore, the optimal choice would be levers made of alloy tool steel X12F1 or 9ХС, with a hardness of 5961HRC. For cutting threads on heat-resistant and alloy steels, a tool made of high-speed steel grades R6M5 or R9K6, with a hardness of 6063 HRC, is suitable.

The price of such blades will be high, so their use is justified only for large volumes of production of threaded parts. For domestic purposes, it is quite acceptable to use lerks made from carbon tool steels U10 or U12.

Among the enterprises that produce such tooling, the highest ratings are those of Izhevsk, Chelyabinsk, Vladivostok, Samara, Bryansk, Nizhny Novgorod (Russia), Orsha, Minsk (Belarus), and Lvov (Ukraine). Foreign-made lechers from UFC (Italy) and CM Tools (Finland) have proven themselves to be excellent in operation.

Tools for machine thread forming

Unlike hand tools, when producing threads on specialized machines, dies perform a reciprocating movement, while the workpiece moves in a screw manner. Such lechers are divided into movable, which is fixed in the slide of the machine, and stationary, installed on its table.

The working area of ​​the fixed ladders consists of three main parts:

• The intake, with the help of which the rod workpiece is captured;
• Profiling, where the thread rolling itself is carried out;
• Calibrating, in the area of ​​which the basic parameters of the thread are calibrated and the product smoothly exits the thread formation zone.

This design eliminates sharp fluctuations in force, which are inevitable due to the operating characteristics of the equipment: high productivity (up to 400 rpm) and the presence of an idle stage, when the slide with the die holder returns to its original position after the next workpiece.

The movable die has a simpler design. Its receiving part in length is approximately 30-35% of the diameter of the original workpiece, while the rise of the profile to the main profiling level occurs at an angle of 470. Moreover, the length of the movable lever is always greater: this eliminates accidental capture of the knurled workpiece during the reverse stroke of the slide.

Machine tools can be used to cut not only ordinary types of threads, but also special profiles, for example, for grease nipple heads, as well as threads for self-tapping screws. For this purpose, a special comb is made on the form-forming part of the lerk, in the grooves of which the necessary sharpening of the end of the fastener is formed.

In order to avoid cracks during long-term use of tools for machine thread shaping, their hardness should be slightly lower than manual ones - within 5658 HRC.

Machine lerks are usually manufactured by the same companies that produce the thread rolling equipment itself.

Tools listed are Italian (from the Sima and Sacma brands), Japanese (Sakamura) and Belgian-made (Malmedie).

It is better to avoid commercially available tools made in China and Taiwan: although its price is much lower, the stability of its performance characteristics and mechanical properties are highly questionable.

Source: https://cs-important.ru/sovety/lerka-dlya-narezki-rezby-raskryvaem-osobennosti-raboty.html

Cutting threads on pipes: tools and operation diagram

Installation of metal pipes can be carried out in various ways. In some cases, welding is used, in others, threaded connections. Since the installation of the pipeline involves fastening a large number of shut-off valves, threading is required. To perform such a technological operation, you need to know how and with what tool to do it. Read about all the nuances of such work further in the article.

Types of taps

A device for cutting threads on pipes is called a tap. There are several types of such tools:

1. Universal. The operation is performed in one pass. The working part of the device contains teeth, which are necessary for marking and performing final cutting. This tool is suitable for soft metal. When it is necessary to process a material with high strength characteristics, considerable effort is required.
2. Complete. This type of device involves the use of various nozzles of the same thread. When working with solid materials, different quantities are used. To obtain the desired result, several steps are performed. First, a marking tap is used. At the second stage, deep cutting is carried out, then the final operation is carried out, which completely forms the edges. It takes much longer to create carvings this way. However, the result is higher quality. Tool breakage during operation is completely eliminated.

Types of taps depending on the method of use

1. Machine. The device has a longer shank. It is used in the socket of electric tools.
2. Machine-manual. The short shank is equipped with square flats. You can use this device manually or insert it into an electric drill. When working manually, a special wrench is used, the so-called tap holder.

Classification of tools by hole type

1. Through. Such nozzles are characterized by an extended approach. Their working area is equipped with a sharp tip, which smoothly changes until the required diameter is obtained. Using such a tool does not cause any difficulties: threads can be cut using any electric drive.

   At the final stage, the device passes through the hole and appears on the other side of the part.

2. Deaf. The working area at the end is cut off similarly to the cutter design, which allows thread cutting to the full depth of the hole.

   The operation must be carried out with caution, since after touching the bottom the tap may become stuck, resulting in its breakage. It is best to cut these holes manually.

Types of taps depending on the working area

The working area of ​​the tool is divided into several types:

• straight;
• screw;
• equipped with shortened grooves.

The teeth can be arranged in a single line or in a staggered pattern. It should be emphasized that universal taps are not suitable for working with very hard or soft materials.

To cut a thread correctly, you need to use only the tool that matches the type of hole and its material.

When working with a tap, you need to accurately select its size so that you can then freely use the mounting bolts.

External thread cutting using a clamp

Cutting threads with a die is not particularly difficult. The work is carried out in the following several stages:

1. First, using a caliper, select the required diameter of the tool.
2. The treated section of the pipe, as well as the inside of the clamp, is lubricated with machine oil.
3. To make it easier to rotate the tool, it is inserted into an additional metal pipe.
4. During initial assembly, the cylindrical product is clamped in a vice. If you need to cut threads during plumbing repairs, you can do this directly on the fixed pipe.
5. The clamp must be fixed on the cylindrical product by smoothly rotating the device. After completing a few revolutions, the tool must be pulled back, turning it in the opposite direction. This is necessary to remove chips that have fallen on the surface.
6. Upon completion of work, the oil is removed.

Die cutting

Pipe threading tools are divided into the following several types:

1. Round. You can work with different diameters of cylindrical structures. Depending on the size of the pipe, the appropriate die size is selected.
2. Sliding. To cut threads of different diameters, a special holder is used.

It should be noted that the price of dies is much lower than the cost of other types of cutting tools, so they are used more often.

The cutting process is carried out in a certain sequence:

1. Using a caliper, the required diameter of the die is selected.
2. The surfaces of the pipe and metal-cutting tools are lubricated. Any lubricant may be used.
3. The device is fixed in the holder. If this is not done, the track will be uneven, the connection will be leaky, and leaks will appear. The die holder must be rotated clockwise.
4. To remove accumulated chips, the tool must be turned in the opposite direction.
5. At the end of the work, all lubricant is removed.

First, rough dies are used. They separate the pipe well, but the work is inaccurate. The final cutting is carried out with a finishing tool.

How to make an internal thread

To do this you need to follow these steps:

1. The hole is prepared for work: accumulated deposits and all kinds of coatings are removed, the surface is thoroughly cleaned.
2. The hole is being lubricated.
3. Depending on the diameter, the required tap is selected.
4. The tool is inserted into the opening.
5. The device rotates clockwise.

To obtain an internal thread, the operation is performed with two taps:

The first allows you to remove 70% of the chips, the second - the remaining 30%.

How to remove a broken tool

When manually tapping internal pipe threads, the taps often break while remaining in the hole. The question arises of how to remove the fragment of the product and clear the opening for further actions.

If the broken piece rises above the surface, you can hook it with pliers and try to unscrew it by rotating counterclockwise. Such removal is successful in 95% of cases. When the chip remains in the hole, ordinary pliers will not help.

To do this, you need to use another method. For example, take a drill and turn on left rotation. The drill is set to minimum speed, so you can try to unscrew the tap.

If this was not possible, the fragment must simply be drilled out with a carbide drill or a diamond tip.

Difficulties when cutting threads

Such a process is always associated with the appearance of the following defects:

1. Torn cuts. This happens when there is no lubrication and the tool is misaligned.
2. The thread has an incomplete profile. This situation is observed with a larger hole diameter or smaller tool cross-section.
3. Skewed thread. The diameters of the opening and special fixture were selected incorrectly.

When cutting in a soft or tough alloy, the hole must be constantly cleared of chips. To do this, the tool rotates several revolutions in the opposite direction.

Cutting should be done in sequential steps using the entire set of taps. It is important to prevent the tool from becoming distorted. Particular care must be taken when working with blind holes. The part must be constantly lubricated with oil. It should be noted that sometimes it is easier to weld a pipe than to cut a thread on it.

Conclusion

We examined the basic principles of threading a pipe from the outside and inside. There should not be any special difficulties during the work. The main thing is to remember: the carving on a rolled metal product does not tolerate sudden movements, so it is important that everything happens smoothly.

Source: https://VseProTruby.ru/rezbovoe-soedinenie/narezka-rezby.html

How to use a pipe thread cutter - rules for cutting threads

:

Any procedure for replacing a certain section of a pipeline involves inserting a new product. Welding can only be used on metal products; It is more convenient to connect plastic pipes using a threaded method, which involves the use of special devices for cutting threads.

General information about thread cutting

During the threading process, a rod or hole is machined. As a result, alternating protrusions appear on the surface - turns or spiral grooves.

The list of main thread characteristics includes:

1. Step. To determine it, you need to measure the distance between the peaks or valleys on adjacent turns.
2. Profile. The coil cross-section can be trapezoidal, triangular or rectangular. Sanitary type elements are equipped only with a triangular profile.
3. Profile angle.
4. Depth. Distance from the top to the bottom of the thread.
5. Diameter. Can be external, middle and internal.

To determine the outer diameter, you will need to measure the gap between two parallel sides of the thread. It is most convenient to carry out this procedure with a caliper at hand. The average diameter is the distance from the top to the base of the profiles located in opposite sections of the part. The internal diameter determines the distance separating opposite depressions from each other.

What are the threads on pipes?

Despite the simplicity of equipping a pipe with threads, it is definitely impossible to do without some recommendations. It is important to be able to distinguish between different types of threads, which can be left-handed, right-handed, inch and metric. Left-handed threads require a counterclockwise movement when screwing a nut onto a bolt. Accordingly, with a right-hand thread everything is exactly the opposite.

Metric thread characteristics:

• Millimeters are used to indicate the structural dimensions of individual elements.
• The profile looks like an equilateral triangle.
• The thread pitch is quite small.

Inch thread has the following features:

• The unit of measurement for designating dimensions is the inch.
• The profile looks like a triangle with equal hips and an apex angle of 55 degrees.
• Has a large step size. The profile of the inch thread is quite large, which gives the thread significant durable characteristics.

Each thread has its own specific purpose. However, right-hand threads are still used much more often than left-hand threads.

How to cut threads and what thread cutting tool is needed

Without the use of special devices, thread cutting on a pipe cannot be carried out. In plumbing stores, pipe threaders are sold under the name pipe threading kit. Quite often, such sets include rather unusual tools - clamps.

Externally, it is the same threaded die, but consisting only of the main functional element. This round frame has the shape of a short cylinder: it is most often made from tool steel. The cutters of this tool have significant strength and durability. The sets are also equipped with holders (ratchet or simple), as well as several additional devices such as pliers, clamps, etc.

When manually threading a pipe, you will need to observe the following points:

1. The pipe must undergo mandatory training. The area where the thread will be cut is cleaned of dirt, rust and paint. It is important to remove everything before the metal base appears.
2. As you apply threads to the pipe, be sure to lubricate the working surfaces and cutters of the tool used. This is done using liquid lubricant. It is applied at the beginning of the work, and as it progresses. At the end of the procedure, the lubricant should be wiped off well with a rag.
3. The end of the workpiece is first freed from the outer chamfer.
4. To achieve good quality, it is important to use a well-sharpened, working tool.

In addition to understanding the process, it is also important to know how to choose the right tool. Threads can be applied not only using the already mentioned dies and clamps, but also with taps. They make it possible to obtain internal threads by cutting grooves for chips. To apply a thread to the surface of a pipe, two similar tools are used at once, having different cutting depths:

• No. 1. Rough tap.
• No. 2. Finishing tap.

Source: https://trubaspec.com/soedinenie-trub/kak-ispolzovat-rezborez-dlya-trub-pravila-narezaniya-rezby.html

Pipe threading

In the practice of performing plumbing work, cutting threads on pipes is a common practice. Threaded connections of tubular elements of water supply systems and autonomous heating systems are made mainly on steel parts. The tubular profile, as is known, has the highest moment of resistance with the same overall dimensions, which predetermines the widespread use of pipes as garden structures, fence posts, etc.

Threading a pipe using a KERN pipe die

Performances

In accordance with GOST 6111, pipe threads are used in detachable connections of pipelines designed for pumping liquid and gaseous working media.

Moreover, relative to water and gas pipes (GOST 3262), it can also be conical, which is explained by the practical convenience of screwing on/screwing on connecting parts.

The angle at the top of the conical thread profile is 60°, and the taper angle depends on the diameter and pitch of the thread, but cannot be less than 26°, otherwise the connection may self-unscrew.

A characteristic feature of all pipe threads - metric and inch - is the rounding of the top of the thread profile, which with standard thread cutting methods is 10% of its radius. This is due to the convenience of cutting pipe threads and the reduction of internal stresses on a relatively small body of metal for pipes of any type and range.

GOST 6357 also provides for metric pipe threads, both cylindrical and conical, although in practice they are used less frequently. The inclination angle of the cylindrical thread profile is 55°, which increases the number of turns in the same cutting area. This increases the complexity of connecting parts of the pipeline, although it increases the tightness.

Other types of threads (thrust, trapezoidal) are not cut on pipes, since this is associated with the appearance of additional stress concentrators, which significantly weaken the cross-section of the material.

Pipe Threading Tools

How to cut threads on a pipe? Excluding mechanized cutting technologies (for example, on screw-cutting lathes), two types of devices are used for cutting threads on pipes: dies (dies) and dies.

A hand die as a tool for cutting pipe threads is a device consisting of two parts - the actual working part, and a body (die holder) equipped with two handles, with the help of which the die is rotated along the outer diameter of the pipe.

An easy-to-use set of threads on pipes is manual, which consists of several sets of dies of the most common diameters. This is explained by the fact that for a high-quality connection, you should use a rough die for the initial pass, and a finishing die of the same diameter for the purpose of calibrating the profile.

You can, of course, use one liner, but its wear in this case will be much higher, especially if the pipeline is made of high-carbon steel.

Unlike a lecher, a cutting die is a more structurally complex tool. It has a ratchet that locks the threading part in a certain position while the handle is turned the next revolution. Therefore, the carving is of higher quality.

Thread cutting on a lathe Thread cutting on a specialized thread cutting machine

In addition to hand-held thread-forming tools, mechanized tools are also used in practice to produce pipe threads.

The most compact and easy-to-use thread cutting machine is equipped with an electric drive.

However, in this case, the cost of the issue turns out to be significantly higher, so electric thread cutters are justified only when you have to make threads on a long section of pipe.

Preparing for slicing

Before threading a pipe, the surface of the metal must be cleaned. Tool wear increases if the original surface of the product is not cleaned of surface rust and scale, has paint residues, etc. Therefore, parts should be thoroughly cleaned before starting work. Persistent scale is removed using organic solvents, and short parts - adapters, leads, etc. – can be cleaned by dipping them in a hot (at least 60 ° C) borax solution.

Pipe stripping

After cleaning, the product is inspected to identify surface irregularities (they are often found on used pipes), as well as if the axis of the element is bent. The slightest bend leads, firstly, to distortion of the cut profile, and, secondly, provokes a sharp decrease in durability when one of the segments of the working part of the tool always experiences an increased threading force.

 Immediately before work, the desired section of the pipe is lubricated. Lubricants with medium viscosity, for example, Industrial 40 oil, are suitable. Thick lubricant (solid oil) can also be applied to the working profile of the die.

Manually cutting pipe threads using the dies included in the pipe threading kit is performed in the following sequence:

1. The part is secured in a workbench vice, making sure that the surface of the material is not deformed (this is especially important for thin pipes made of low-carbon steel). The load must be distributed over at least three points located at an angle of approximately 120° relative to each other.
2. The lead-in chamfer is removed at both ends. To do this, you can use a file to form a cone with a height of at least 1.52 mm and an angle of 4560° around the entire perimeter of the end part. You can do without this transition, but then the force of inserting the die into the metal increases, and the durability of the die decreases.

   Threading dies

3. By rotating the die holder with the handles, the thread is cut approximately 56 revolutions. After this, the operating force increases, which is associated both with the frictional effect of the chips and with a decrease in the amount of lubricant between the contact surfaces. Therefore, the process is stopped and lubricant is added to the working area, while it is better to move the tool back one revolution.
4. After passing the rough die, use the finishing die, which is usually included in the kit. The order of work is the same. Rotation is always clockwise. It is important not to increase the cutting rate, since this increases the temperature of the tool and additionally loads the pipe with bending forces.

The choice of die material should be made in favor of tool steel grades X12F1 or even high-speed cutting steel R6M5. Tools made in China are not of high quality, since dies from China are, at best, made from unalloyed tool steels.

Obtaining a threaded profile using clamps

Clupps are manufactured with sliding and fixed dies. It is more convenient to use a tool of the first type, which is sometimes called Mayevsky’s clamp. A design feature of such a device is the presence of radial one- or two-sided dies.

There are seven holes in the tool body: four for the working die and three for the guide die. For movement in the radial direction, faceplates are provided, which are pressed against the die body with clamping rings.

This design eliminates the possibility of re-passing the thread (as in the previous version).

The work is carried out as follows:

1. The part prepared for thread cutting is placed in a vice, the end is prepared for cutting, and then a die with spread dies is put on the product.
2. Bring the die holder to the forming surface of the pipe and secure it there using clamps (included in the clamp set).
3. The dies are installed, and the shaping of the threaded section begins with the feeding force.
4. When the die is turned back, the ratchet disengages the dies from engaging the pipe surface, after which the faceplate rotates the next revolution and thread cutting continues.

Device

The disadvantage of clamps is their massiveness, as well as the need for more careful care. However, technological conveniences completely compensate for these everyday limitations.

Source: https://stankiexpert.ru/tehnologii/narezka-rezby-na-trubakh.html

Thread cutting: features of work on a pipeline, tools and devices - Machine

Welding could be used for rolling metal pipes, but what to do when you need to connect two pipes made of different materials? This is where the joining method comes to the rescue by cutting threads on the pipes and then connecting them. What it is and how it is performed, what tool can be used will be discussed in detail in the material presented below.

Types of threaded connections

First of all, it should be noted that you do not need to have any special skills to perform these actions. But you need to be able to distinguish the type of thread on a pipe. For example, it is important to distinguish between inch and metric knurling, left and right. In general, there are a large number of types, but these are the ones most often used - inch and metric.

The distinctive characteristics of the inch and metric types are as follows.

Inch type of thread on pipes:

1. All items are measured in inches.
2. The presence of a profile in the shape of an isosceles triangle with an angle of 55 degrees at the upper corner.
3. Present big step. Consequently, this profile is larger and this type of cutting has higher strength.

Metric type:

1. All elements are measured in millimeters.
2. The profile is distinguished by the shape of an equilateral triangle.
3. Smaller step.

IMPORTANT! Cutting on pipes for water supply is carried out in inch units, and for fasteners, measurements in mm are used.

Below we will consider what types of carvings there are.

• Right. This is if the nut is screwed onto the bolt in a clockwise direction.
• Left. In this case, the nut is tightened in the opposite direction.

High-quality cutting on a pipe can only be achieved if the volume of the drill or rod for making the hole is accurately selected.

Advice. Experts recommend selecting a rod with a volume 0.003 cm less than the dimensions of the external thread volume.

Each pipe thread is characterized by individual parameters, which are regulated by GOST 621181.

So, for example, a conical thread, according to GOST requirements, is distinguished by the protrusion of its turns. These regulatory documents also define the groove when cutting. And according to GOST 621181, the cutting profile is determined.

Required Equipment

This pipe set usually consists of:

1. pairs of dies or clamps used for processing pipe materials of different diameters;
2. a holder with a ratchet (although it can be without it). A die or die is inserted into it.

This set can also be equipped with some additional tools. These could be pliers, a clamp, and the like.

We will talk about all these tools in more detail later.

Tools for manual processing - tap

When cutting, use a set consisting of a pair of taps. They differ from each other in terms of the depth of the cut. So, for example, the first number is taken for roughing, and the second number for finishing.

Using the die

Depending on the shape of the slicing tray, there are:

1. round;
2. sliding;
3. split;
4. whole.

Using a device such as a ladder, you can quickly prepare any type of tubular product for connection.

The die must be aligned with the end part of the tubular product strictly perpendicularly. If misalignment is allowed, there is a possibility of a thread breaking, or the diameter of the thread may change. In both cases, the final result will be unsatisfactory.

It is recommended to perform all work with the lecher smoothly, avoiding jerking. When operating with this device, you should lubricate the cutters and the surface part of the thread from time to time.

Upon completion of the final turn, the die must be returned up and the threads are passed again.

Application of a cleat

A cutting die is no less effective than a die. This cutting device is a more modern tool and is universal. The die consists of a holder with grooves. They contain replaceable cutters, which can be easily changed if they become dull during operation.

A special feature of this carving device is that it requires little effort on the part of the master. It should also be noted that working with such a device is much safer than with other similar tools. The thing is that the clamp holder is equipped with guides inside, which significantly increase the accuracy of the reproducible actions of this device.

Ratchet clamps

Using these mechanisms for thread rolling is not difficult. The outermost part of the pipe “sits” into the holder guide. The thread is cut using a clockwise rotational motion. During production, one must not forget about lubricating the surface part.

At the end of cutting, the clamps are turned back out and once again passed over the area to be treated.

Using a power tool

A power cutting tool differs from its manual counterparts in that it has an electric motor.

This allows you to cut threads in the shortest possible time. The power tool also allows you to perform actions quickly and efficiently. Moreover, the process does not require much physical effort.

When starting to work with a power tool, you need to fix the pipe in the clamp and press the “start” button. Cutting is done in seconds. After all, the workpiece does not need to be fixed in a vice, but the power tool itself is attached to it. Therefore, these tools stand out for their portability and convenience.

Cut on the outside

Otherwise, the work will not be done well. A screw is used for fastening. A steel plate - a cracker - is placed between it and the die so that it does not crack when pressed.

Round devices are attached to the easy-holding knob with several screws - stops.

By performing manual actions using sliding views, it is possible to obtain threaded threads, this is when there are small differences in the diameter of the rod. But when working manually with solid dies, this cannot be allowed. For example, if the rod is of reduced diameter, then the cutting will be incomplete.

Cut from the inside

When forming the internal knurling, you should know that the tap has a fence side. This is his end. This is needed for this job. The middle section of the mechanism is the calibrating section. He determines the direction. The tail part has a head with a square section, which serves to support the tap in the driver when operating on the inside.

Basic cutting locations

The joints on the assortment for water supply are made in such a way that a cylindrical knurling is made on their end parts, for which you will have to use a special cutting machine. And then the end parts of the pipes are fastened using connecting parts.

Watch the video

In this case, a long or short cylindrical knurling is used, in which the two final turns made by the machine are called a run. It is formed due to the design features of the thread-cutting device.

The run-out allows the coupling to jam on the pipe product, therefore, the design with the sealant material is very tight.

The length of a short type of knurling cannot be more than half the length of the coupling.

And for permanent joints using shaped parts, a short type is used. Such a joint can only be dismantled by cutting it.

The dimensions of the short and long types of threads made by a special apparatus vary depending on the diameter of the pipe assortment.

To save metal, pipes with thin walls are installed in gas supply and heating networks. Since in this case the thickness of the walls is less than that of the water pipeline, then when thread rolling, the critical value of the walls of the pipes must be no less than that recommended for these pipes.

Action steps

Thread cutting on pipes of small and large diameters is carried out according to the same principle. Having made a certain number of turns, the thread-cutting mechanism scrolls in the opposite direction. This is necessary so that the working area is cleared of metal shavings.

• Having prepared the grinder for work, you should process the section of the metal pipe with formed corrosion or with old threads.
• Watch the video

Advice. There is no point in trying to restore old threads on pipes of large or small diameter; it will not meet the required level of tightness, which will result in leakage.

Next they move on to chamfering, otherwise the dies will be difficult to screw on. The area where the knurling will be located must be lubricated with oil.

After this, the thread-cutting device holder is switched (clockwise). This is recommended so that the treated area is freed from any remaining chips. At the end, you need to remove all remaining sawdust and oil from the treated area.

To determine the correctness of the work performed on a large or small diameter assortment, it is recommended to screw the part that is prepared for installation onto the pipe. In this way, it is determined whether the cutting dimensions are sufficient and how well it is made. Only after a thorough check can you proceed to installation work.

Main reasons for marriage

Even the highest quality pipe threading machine does not guarantee that defects will not occur. But, if it turns out to be defective, then such a product cannot be used for work. For these reasons, all work performed by a threading machine must be carried out with extreme care and skill.

Watch the video

Let's look at the main reasons for marriage.

• Using a low-quality machine for work. Moreover, the entire cutting kit must also be of good quality. For example, if there is rust on the parts of the kit, this will undoubtedly lead to poor quality of the work performed. In the same way, any dull part of their kit will ruin the workpiece. Therefore, it is better to choose a good quality machine for the job; this is the only way to get the expected end result.
• If cutting is performed without chamfering pipes and without using lubricant. If you do not remove the chamfer, the die will not sit well, which will undoubtedly affect the final result of the work. And not only is it important to pay attention to the chamfer, but if you do not apply lubricant, you can expect cracks in the thread, and it will be cut with threads breaking.
• You should not put in too much effort; this method of work may result in the cutting being disrupted.
• Unacceptable difference in dimensions of rolled pipe and die or die.

It is clear that it is not difficult for a professional master who has a “full” hand to perform these actions.

But a home craftsman with little experience does not need to be upset. If you carefully read all the recommendations and carry out the work without haste and carefully, then a high-quality result of the work is guaranteed.

Watch the video

Source: https://regionvtormet.ru/metally/narezka-rezby-osobennosti-provedeniya-rabot-na-truboprovode-instrumenty-i-prisposobleniya.html

Thread cutting: features of work on the pipeline, tools and devices

When a pipeline is being repaired, it becomes necessary to insert it into the existing pipeline. If metal pipes are laid, you can use welding. To connect shut-off valves, you must have a special tool for cutting threads on pipes. Moreover, its production with such a device can be easily done at home with your own hands.

In most cases, a threaded connection remains the main type of joining of metal pipes. It has several parameters that are taken into account when installing the fittings. Correctly selected dimensions allow you to create a reliable and tight connection.

To work with a thread cutter, it is necessary to distinguish between types of thread, its parameters and characteristics.

Inch and metric cutting

Several parameters are considered to be a characteristic difference:

• The part measurement is expressed in inches.
• The thread profile resembles an isosceles triangle, the apex of which is 55 degrees.
• Features a large step.
• Large profile.
• High strength.

In Russia, all measurements are performed in the metric system. Threading a threaded connection was no exception . The characteristic differences are:

• Dimensions are indicated in millimeters.
• The profile resembles an equilateral triangle.
• A small step.

To connect water pipes, the inch system is used, the manufacture of fasteners is done in the metric system. If the reinforcement is screwed in a clockwise direction, the connection is called right-handed. If on the contrary, the thread is considered left-handed.

Types of tools

For the manufacture of threaded connections, the industry produces special cutting devices. They are designed to perform certain technological operations. A screw-like tool for creating internal threads is called a tap.

The device cuts chip grooves on the body of the pipe. For fastening in the driver, the tap has a long shank. The tool is produced in accordance with the current standard.

There are special tables that indicate the size of the tap, its number and type.

The cutting kit includes two taps. Their main difference is the depth of groove cutting:

• Chernova - No. 1.
• Finishing - No. 2.

Die device

This device is sometimes called a lerka. The tool is equipped with a kind of nut with several holes. It is this that creates the cutting edges.

The industry produces lerks of various shapes:

• Klupp.
• Round.
• Split.
• Sliding.
• Whole.

Description of the clamp

It differs from other devices in its special guide, which centers the die relative to the pipe. The device can be electric or manual. For use at home, when cutting will occur no more than two or three times, it would be more rational to work with a manual clamp. Its cost is much less than an electric tool.

This tool is very convenient to work with. The thread is very clean and reliable. The light weight of the device and the simplicity of the design allow you to quickly replace the cutters.

The most important characteristic of a clamp is the material from which it is made. Expensive tool steel is used to create the die. But carving is created only by incisors. They must be highly durable.

The clamp does not have expensive non-functional elements. Therefore, a set of dies costs much less. The cost of threading a stainless steel pipe is dramatically reduced. Home craftsmen, not wanting to incur large financial losses, prefer to work with such a tool.

Self-cutting

There are several tools you can use to do the job:

Which tool set to choose depends on several factors. This is especially true for the type of carving. After all, it can be internal or external. After selecting a die, there are several steps to follow.

• The old thread is cut off. Don't try to restore it. It will still remain leaky and leakage will occur. The cut should be strictly perpendicular to the longitudinal axis of the pipeline.
• If there are traces of corrosion on the pipe, the segment must be completely removed.
• To make it easier to screw the die onto the pipe, its end must have a lead-in chamfer.
• For easier screwing, the location of the future thread is lubricated with oil.
• After cutting several turns, the die needs to be scrolled back. Performing sequential torsion forward and backward, a thread of the required length is cut.
• After the operation is completed, metal filings are removed.
• To check the quality of work, you need to screw the intended part onto the pipe.

If everything is in order, the number of turns corresponds to the mating part, you can seal the connection and begin installation of the pipeline system.

Source: https://tokar.guru/metallicheskie-izdeliya/prisposobleniya-dlya-narezki-rezby-na-trubah-raznogo-diametra.html

Thread cutting tools. Types and work. Application

A threaded connection is one of the most popular ways of fastening various parts and elements. It is not always possible to purchase various fasteners that already have threads applied, so you need to cut them yourself. For this purpose, specialized thread cutting tools are used. With their help, it is also possible to renew previously worn or otherwise damaged threads.

There are 3 types of tools used for thread cutting:

The cutting tool differs not only in diameter, but also in the type of thread created. It can be metric or inch. Metric is used on the vast majority of fasteners. It is used in mechanical engineering, household equipment and other areas. Inch threads are used exclusively on plumbing elements. In some countries, metric threads are not used at all, and all fasteners are made using inch threads.

Another important difference between such a tool is the direction of the thread being created. It can be left or right. You cannot use one tool to cut threads in both directions if it is not universal.

Tap

A tap is a cylindrical tool that is designed for cutting internal threads in pipes and nuts. Its surface has protruding ribs, which, when screwed into hollow metal elements of suitable diameter, create helical grooves, cutting out chips. As a result of screwing in, the tap creates a thread.

This device is a small metal rod made of high-quality hard steel, at one end of which there is a cutting part, and at the other a shank for connecting a wrench. There is a recess along the surface of the tap, through which the removal of cut chips is ensured. The most convenient for use are tools that have 3-5 grooves for chip removal.

They clog much less and provide a clean surface without visible deformation. After cutting the thread using a tap, the bolt or stud is screwed effortlessly over the entire surface.

Using a tap, you can cut a thread or calibrate it if it is damaged.

This tool comes in three varieties:

Hand taps are usually offered in a set of 2-3 tools of the same diameter. The former provides rough thread cutting, while the latter creates a high-quality, smooth profile that allows bolts or studs to turn easily. The order of use of the taps that come in the set is indicated by numbers on their body.

Machine tools are designed for cutting threads on machines. They have a different groove profile for faster chip removal. In this case, the shape of the shank is adjusted to fit into the chuck on the machine.

Nuts are used specifically for nuts. They are easy to recognize because they are the shortest. Since this tool is designed for cutting threads only in nuts, which are usually small in width, it is made very short. In this regard, its length allows you to make a maximum of 12 turns. Nut taps can also be roughed or finished. The roughing only creates the initial thread for screwing in the intake part of a longer tool.

To properly secure a hand- or nut-type tap, a special wrench is used, which is mounted on the shank. The rake angle of a tap determines its application and the metal it can work with. The angle with an inclination of 5 to 10 degrees makes the tool convenient for processing steel. A slope of 0 to 5 degrees is intended for cast iron. Taps with sharpening from 10 to 25 degrees are used for non-ferrous metals and their alloys.

Die

The die (die) is used to create screw threads on bolts and studs. It is a round washer with a central hole, which has several protruding ribs with a sharp edge. The die cuts and calibrates external threads in one pass.

It is usually used for cutting threads on rods with a diameter of up to 52 mm. The standard thickness of the dies is from 8 to 10 turns. The angle of the cut protrusions on the die may vary. A tool with an angle of 40-60 degrees is used for through passage.

In the event that it is necessary to cut the thread close to the stop, a die with an angle of 90 degrees is used.

In order to obtain a high-quality cut thread, it is necessary that the diameter of the rod that will be processed be 0.3-0.4 mm larger than the internal size of the die. Also, when using this tool, it is worth considering that chamfering on the edge is required. In order to hold the die, special cranks are used.

The die can be solid or cut. The solid one has protruding teeth for cutting into the metal over the entire surface. Using such a tool requires serious effort. Much more popular are cut dies, which have separated working parts, which reduces the contact area. This makes it easier to remove chips and reduces friction.

The die can be used for cutting threads on the right or left side. There is also a universal tool that works equally well in both directions. It is designated by the marking LN .

Klupp

Klupp is practically the same die, but significantly larger. It is a system of cutters installed directly into the holder, which also serves as a guide. Typically, this thread cutting tool is used for cutting external threads on pipes as well as thick metal rods. Clamps offered on the market usually have not only a metric stroke, but also an inch stroke. Clamps are usually used by plumbers to prepare pipes.

The dies are sold as a set, which includes one holder and several dies. The attachments can be easily changed. There are also electric clamps that are fixed on the pipe and they themselves cut the thread on it. Thanks to their own gearbox, they are able to create great forces, even with a weak electric motor.

Features of using a thread cutting tool

In order to obtain a high-quality thread with a smooth surface, the workpiece with which the work is being done must be secured in a vice. If this is not possible, for example when re-threading a water pipe that is already installed, it should be held with a pipe wrench.

In order to get a high-quality result, it is also important to choose the correct diameter of the thread cutting tool. If a tap is used, it should be 0.2-0.3 mm larger than the hole into which it is screwed.

If a die or die is used, then, on the contrary, the rod should be larger, by about 0.3-0.4 mm.

It is recommended to prepare lubricant before starting work. This will reduce friction and reduce stress. In addition, the presence of lubricant helps to avoid the formation of burrs and excessive overheating of the part.

When using a die or tap, it is worth making several turns without using a lubricant. This will allow the teeth to cut firmly into the metal at the correct angle. If you immediately try to cut a thread on a slippery surface, misalignment may occur.

As a lubricant, you can change machine oil, grease, diesel fuel and even lard.

When working with aluminum, it is recommended to use kerosene as a lubricant. For very hard steels, the hardness of which is almost equal to the tool used, it is worth using drying oil.

When using thread cutting tools you need to do it correctly

After completing several turns, it is necessary to reverse the process. This will effectively remove the resulting chips and improve the surface of the formed protrusions. In this case, the previously applied lubricant should be periodically renewed. If there is no machine oil, grease or lard, as a last resort, you can use very soapy water. It is significantly inferior in viscosity, but is quite capable of improving the passage of the tool.

If you are cutting an internal thread, you should pay attention to the fact that first you take a tap that has an incomplete thread. It can be recognized by its tapered tip and the marking “1”. It makes shallow cuts, which can hardly be called full-fledged carving. After this, a more even tap is used, on which a marking in the form of the number “2” is applied. As it passes, it deepens the existing groove and makes it suitable for screwing in bolts and screws.

Some sets have a tool marked “3”. It allows you to prepare a threaded connection with even better quality, bringing it to perfection. When changing taps, it is worth considering that subsequent addition of lubricant is a prerequisite. Its absence can lead to early wear of the tool.

After threading tools are removed from the treated surface, they should be wiped with a dry cloth. This is especially important if soapy water was used as a lubricant. The same goes for lard oil. These substances are quite sticky, so they promote the adhesion of dust and dirt, which will subsequently lead to clogging of the thread and its sticking when screwed in.

Related topics:

Source: https://tehpribory.ru/glavnaia/instrumenty/instrumenty-dlia-narezki-rezby.html