How to cut a thread with a tap

How to cut a left-hand thread with a tap? — Metals, equipment, instructions

Threaded connections are simple, reliable, and make it possible to adjust the tightening, as well as disassemble and assemble parts and mechanisms. They are widely used in various mechanisms, devices, and devices.

 Threads can be external (screw) or internal (nut). There are cylindrical triangular (sawtooth), conical triangular, rectangular, trapezoidal, thrust, and round threads. The most widely used is the cylindrical triangular or, as it is also called, fastening thread, figure No. 1.

Figure No. 1 – Thread elements on a bolt

1 - depth;

2 - top; 3 - step;

4 — depression;

5 - outer diameter;

6—inner diameter.

Internal thread cutting:

First of all, you need to choose the right drill bit for drilling the hole.

You should know that if you drill a hole for a thread with a diameter that exactly matches the internal diameter of the thread, then the metal squeezed out during cutting will put pressure on the teeth of the tap, which can cause the thread to end up with torn threads, and the tap may break.

If you drill a hole that is too large in diameter, the thread depth will be incomplete and the connection will be weak.
When drilling a blind hole for a thread, its depth must be made slightly larger than the part being cut, otherwise the thread will be incomplete in length.

Thread cutting is carried out in the following sequence: mark the drilling location with a center punch; secure the part in a vice; drill a hole; insert the tap into the hole (Figure 2) strictly vertically (along the square); put a crank on the tap, press it against the tap with your left hand, and turn it to the right with your right hand until the tap cuts into the metal on several threads and takes a stable position; take the knob by the handles with both hands and rotate it with the hands intercepted every 1-2 turns. Thread cutting is greatly facilitated if you use a tap to make 1-2 working turns to the right and 1-2 turns to the left; Having finished cutting, the tap is unscrewed from the hole, then once again driven along the resulting thread.

Figure No. 2 - Cutting internal threads with a tap:

a — installation of the tap in the hole;

b - thread cutting.

Rules for working with taps:

When cutting threads in deep holes, in soft and tough metals (copper, aluminum, bronze, etc.), the tap must be periodically unscrewed from the hole and the grooves must be cleared of chips; You need to cut a thread with a full set of taps - rough, medium and finishing.

The middle and finishing taps are inserted into the hole without a driver and only after the tap follows the thread correctly, a driver is put on the head and threading continues;
during the cutting process, you need to use a square to carefully ensure that there is no skew of the tap; The thread cutting area should be lubricated with oil.

External thread cutting:

At home, it is done with dies by hand.
The diameter of the rod for external threads should be 0.3-0.4 mm less than the outer diameter of the thread being cut. Deviations from this rule are not permitted.

Cutting an external thread with a round die is done in the following order:
a chamfer is removed at the upper end of the rod, which ensures that the die cuts into the metal;

The rod is clamped vertically in a vice so that its protruding end is 20-25 mm longer than the length of the part being cut (Figure No. 3); Place a die fixed in a knob on the rod and rotate it with slight pressure so that the die cuts into about 1-2 threads without distortion. After this, lubricate the rod with oil and smoothly rotate the knob 1-2 turns to the right and 1/2 turn to the left.

Thread cutting with sliding prismatic dies (Figure No. 3) is performed as follows: a chamfer is filed at the end of the rod; install dies into the die; clamp the rod in a vice; put the clamp on the rod and move the nuts tightly with a clamping screw; lubricate the dies and the rod with oil; The die is turned 1 - 1.5 turns clockwise, then 1-4, 1-2 turns back, and so on until the end of the thread; Having cut the thread, screw the die to the end of the rod, tighten the dies with a screw and pass the thread a second time; check the thread with a nut of the appropriate diameter; at the end of the work, the dies are removed from the die, cleaned of chips, wiped and lubricated with oil; wipe the clutch.

Figure No. 3 - Cutting threads using a die

a — Cutting threads with a round die
b — Cutting threads with prismatic dies

Source: https://spb-metalloobrabotka.com/kak-narezat-levuyu-rezbu-metchikom/

How to cut a thread by hand - Buildman

The question of how to cut a thread with a tap arises in cases where a pre-made hole needs to be prepared to accommodate a bolt, screw, stud or any other type of threaded fastener. In such situations, it is the tap that is the main tool that allows you to quickly and accurately cut an internal thread with the required geometric parameters.

Manual cutting of internal threads is performed using metalworking taps complete with a wrench

Types and areas of application of taps

Internal thread cutting can be done manually or using various types of machines (drilling, lathe, etc.). The working tools that perform the main work of cutting internal threads are machine-hand or machine taps.

Taps are divided into different types depending on a number of parameters. The following principles for classifying taps are generally accepted.

1. According to the method of rotation, a distinction is made between machine-manual and machine taps, with the help of which internal threads are cut. Machine-hand taps equipped with a square shank are used in conjunction with a special device with two handles (this is the so-called tap holder). With the help of such a device, the tap is rotated and cuts the thread. Thread cutting with a machine tap is carried out on metal-cutting machines of various types, in the chuck of which such a tool is fixed.
2. Based on the method by which internal threads are cut, a distinction is made between universal (through) taps and complete taps. The working part of the former is divided into several sections, each of which differs from the others in its geometric parameters. The section of the working part that first begins to interact with the surface being processed performs rough processing, the second - intermediate, and the third, located closer to the shank - finishing. Cutting threads with complete taps requires the use of several tools. So, if a set consists of three taps, then the first of them is intended for roughing, the second for intermediate, and the third for finishing. As a rule, a set of taps for cutting threads of a certain diameter includes three tools, but in some cases, when products made of particularly hard material are processed, sets consisting of five tools can be used.
3. Based on the type of hole on the inner surface of which it is necessary to cut a thread, taps for through and blind holes are distinguished. A tool for processing through holes is characterized by an elongated conical tip (approach), which smoothly passes into the working part. Universal type taps most often have this design. The process of cutting internal threads in blind holes is carried out using taps, the conical tip of which is cut off and performs the function of a simple milling cutter. This design of the tap allows it to cut threads to the full depth of a blind hole. To cut a thread of this type, as a rule, a set of taps is used, driven manually using a wrench.
4. According to the design of the working part, taps can have straight, helical or shortened chip removal grooves. It should be borne in mind that taps with grooves of various types can be used for cutting threads in products made of relatively soft materials - carbon, low-alloy steel alloys, etc. If threads need to be cut in parts made of very hard or viscous materials (stainless, heat-resistant steels, etc.), then for these purposes taps are used, the cutting elements of which are arranged in a checkerboard pattern.

A good tap is made of high-quality tool steel, looks neat and has smoothly machined turns and grooves

Taps are usually used for cutting metric threads, but there are tools that can be used to cut pipe and inch internal threads. In addition, taps also differ in the shape of their working surface, which can be cylindrical or conical.

Preparing to cut internal threads

In order for the process of cutting internal threads using a tap to not cause any particular difficulties and result in a high-quality result, it is necessary to properly prepare for this technological operation.

All methods of cutting threads using a tap assume that a hole with the appropriate diameter has already been made in the workpiece.

If the internal thread that needs to be cut has a standard size, then a special table with data in accordance with GOST can be used to determine the diameter of the preparation hole.

Table 1. Diameters of holes drilled for standard metric threads

If the thread that needs to be cut does not belong to the standard category, you can calculate the diameter of the hole to make it using a universal formula. First of all, it is necessary to study the marking of the tap, which must indicate the type of thread being cut, its diameter and pitch, measured in millimeters (for metric).

Then, to determine the cross-sectional size of the hole that needs to be drilled for the thread, it is enough to subtract the pitch from its diameter. For example, if a tool marked M6x0.75 is used to cut a non-standard internal thread, then the diameter of the preparation hole is calculated as follows: 6 – 0.75 = 5.25 mm.

For standard threads belonging to the inch category, there is also a table that allows you to choose the right drill with which to carry out the preparatory work.

Table 2. Diameters of holes drilled for inch threads

An important question to obtain a high-quality result is not only the question of what is used to cut the thread, but also what drill to use to make the preparation hole. When choosing a drill, you need to pay attention to the parameters and quality of its sharpening, as well as to ensure that it rotates in the chuck of the equipment used without runout.

The sharpening angle of the cutting part is selected depending on the hardness of the material that needs to be drilled. The higher the hardness of the material, the greater the sharpening angle of the drill should be, but this value should not exceed 140°.

When drilling blind holes, control the drilling depth

How to cut threads correctly? First you need to select tools and consumables:

1. an electric drill or drilling machine capable of operating at low speeds;
2. a drill whose diameter is calculated or selected using reference tables;
3. a drill or countersink, with the help of which a chamfer will be removed from the edge of the prepared hole;
4. a set of taps of the appropriate size;
5. manual holder for taps (drives);
6. bench vice (if the product in which the thread needs to be cut needs to be fixed);
7. core;
8. hammer;
9. machine oil or other composition, which during the processing process must be used to lubricate both the tap and the thread section being cut by it;
10. rags.

Diagram of thread cutting with a tap

Features of the technology

When cutting internal threads with a tap, the following algorithm is used.

• In the place on the surface of the workpiece where the hole for threading will be drilled, it is necessary to form a recess for a more accurate entry of the drill, using a core and a regular hammer. The drill is fixed in the chuck of an electric drill or drilling machine, on which low rotation speeds of the tool are set. Before starting drilling, the cutting part of the drill must be treated with a lubricating compound: a lubricated tool enters more easily into the structure of the material being processed and creates less friction in the processing area. You can lubricate the drill with a piece of ordinary lard or grease, and when processing viscous materials, machine oil is used for these purposes.
• If it is necessary to cut threads in small parts, they should first be fixed using a bench vice. When starting drilling, the tool fixed in the equipment chuck must be positioned strictly perpendicular to the surface of the workpiece. You should lubricate the tap regularly and ensure that it does not warp and moves strictly in the given direction.
• At the entrance to the hole, as mentioned above, it is necessary to remove the chamfer, the depth of which should be 0.5–1 mm (depending on the diameter of the hole). For this purpose, you can use a larger diameter drill or countersink, installing them in the chuck of drilling equipment.
• The process of cutting internal threads begins with tap No. 1, which is the first to be installed in the driver. We should not forget about the lubricant, which must be applied to the tap for threading. The position of the tap relative to the hole being machined must be set at the very beginning of the work, since later, when the tool is already inside the hole, this will not be possible. When cutting a thread with a tap, you must adhere to the following rule: 2 turns of the tap are made in the direction of cutting the thread, 1 - against the direction. When the tap makes one revolution back, chips are thrown off its cutting part and the load on it is reduced. Thread cutting with a die is performed using a similar technique.
• After cutting the thread with tap No. 1, tool No. 2 is installed in the driver, and after it – No. 3. They are processed according to the method described above. When cutting threads with taps and dies, you need to feel when the tool begins to rotate with force. As soon as such a moment occurs, you should turn the knob in the opposite direction to throw the chips off the cutting part of the tool.

The harder the material being processed, the more abundantly the tap must be lubricated during the thread cutting process.

Before making internal threads with a tap or cutting threads with a die on external surfaces, you should thoroughly study these procedures and strictly follow the rules for their implementation. Only in this case can you count on the result satisfying you with its quality and accuracy.

Source: https://a-buildman.ru/kak-narezat-rezbu-metchikom-vruchnuyu.html

How to properly cut a thread with a tap

Often, when performing home repairs, it becomes necessary to make threads - external or internal. In order not to involve specialists in this, but to do it yourself, you need to purchase a special tool. Cutting with dies and taps does not require any special skills or abilities. It is enough to know their types and technical parameters.

A little about the features of the tool

The first step is to decide on the type of thread. It is divided into 2 main types: metric and inch. The first one with the left direction is most often used. In order not to measure the distance between the grooves, you can find out the type by the shape. A metric thread in cross-section is an equilateral triangle, and an inch thread is an isosceles one.

Types of thread

Which products use a certain type of thread? Fasteners use metric, while water pipes use inch. In addition, you need to take into account the following factors that influence the process of cutting connecting elements.

1. If the thread is intended to be connected to a finished part, its geometric dimensions must be appropriate.
2. When manufacturing complete fasteners, it is recommended to use the metric type.
3. The diameter of the workpiece must be different from the thread size. For the outside - to a lesser extent, for the inside - to a greater extent.

Self-cutting of threaded connections is carried out using dies and taps. They are made of high-strength steel with a standardized working fluid size.

Outdoor

The die is a nut with internal slots and external clamps for turning the tool. It can be of various shapes - round, square or hexagonal. If the work is carried out at home, you will need a vice to fix the part.

Die holder and dies

Before performing work, the main thing is to choose the correct diameter of the workpiece. It should be 0.2-0.3 mm smaller than the size of the future thread. For metric, you can use the data from the table.

The workpiece should be prepared in advance. If its cross-section is not a circle, you need to turn it. Then a conical chamfer is removed from the end part to mark the first turn of the thread.

Next you need to follow the instructions exactly:

1. Having secured the workpiece in a vice, the correctness of its location is checked.
2. Installing the die into the die holder. Its surface must be in the same plane as the surface of the workpiece end.
3. The first turn is performed with little effort. It is important to make turns in the right direction.
4. Having reached the lower limit, the die must be turned in the opposite direction.

External thread cutting

One such pass will not be enough to form a thread with good geometry. It is recommended to repeat the procedure 3-4 times until the die is freely screwed onto the workpiece. To check the quality, tighten a nut of the appropriate diameter. If force is observed, you can treat the outer part of the workpiece with fine-grained sandpaper.

Internal

Taps must be used to form internal threads. They are a cylinder with an external notch. If you need to process small parts with a diameter of up to 20 mm, you can use a manual type of tap. Larger sizes require machining using a machine.

Working with a tap

It is best to use a complete set of taps. It includes three parts that are designed for roughing, intermediate and finishing threaded holes. If you have a drill in your home kit, it is recommended to purchase taps with a tail mount.

The workpiece should be fixed. If this is a large-sized part, this can be done using clamps. For small products, a vice is used. Having secured the part, its location relative to the tap is checked.

The axis of the latter must be strictly perpendicular to the plane of the workpiece. The first pass will be made with great effort. Do not forget that for this you need to use a rough cutting tap. Having formed the primary thread, a tap is used for the intermediate thread.

And only after it can you begin final processing.

To reduce friction, specialists use solid oil or a similar product. In this way, mechanical damage to the part can be avoided. The formed thread must have the same geometry along its entire length. Otherwise, the connection strength may be lost.

Source: http://ooo-asteko.ru/kak-pravilno-narezat-rezbu-metchikom/

Tapping threads. How to cut threads by hand?

Tapping threads

Tapping a thread is a creative process that should be approached responsibly and “not indifferently.” After all, the success of its sealing, the ease of tightening the nuts and the absence of leaks depends on how the thread is cut.

The quality of a threaded connection depends largely on a good thread. To cut a thread with a tap yourself, you have to put in a lot of effort, but the result will pleasantly please you.

Tapping threads - how to cut threads by hand?

How to cut threads with a thread-cutting device was described earlier. A thread-cutting device differs greatly from a tap device, but the principle of cutting threads with both tools remains the same.

A tap is a metalworking and turning tool, its shape somewhat reminiscent of a long rod. Inside this very rod there are cutting elements, with the help of which threads are cut manually.

The tap can be used for more than just cutting new threads. Using this tool, you can also restore the thread, making it look like “new”.

According to the principle of operation, taps are either manual or machine. Machine taps are mounted on a lathe, and thread cutting occurs automatically.

How to choose the type of tap?

To cut threads by hand, you first need to choose the right type of tap. The choice of tap for thread cutting depends primarily on:

• Thread pitch;
• Profile;
• Forms of threaded connection;
• Admission;

In addition, the choice of a specific tap is also influenced by the material of the parts on which the thread will be cut. The main choice of a tap primarily depends on the diameter of the thread being cut.

Tapping threads by hand

Thread cutting with a tap occurs as follows. The part to be threaded is secured in a vice or other device. The main thing is that the part is securely fixed in the device, since when cutting a thread with a tap you will need to apply a lot of force.

Then a hole is drilled in the part for threading with a tap, depending on the type of thread - blind or through. The diameter of the hole being drilled should be slightly smaller than the diameter of the cutting elements of the tap.

Be sure to chamfer the top edge of the hole for cutting threads with a tap. After this, the tap is taken and installed in the drilled hole, which should be located in the vice with the chamfer facing up.

Threading with a tap is done clockwise, all the time pressing the tap into the hole. The tap must be pressed in smoothly, without unnecessary jerks, gradually turning it until a clean and even thread is obtained.

Having made several turns with the tap clockwise, it is returned in the opposite direction, thereby getting rid of the accumulated metal shavings.

During thread cutting, it is necessary to cool the tap in a timely manner, otherwise the tool can easily be damaged. If an aluminum thread is being cut, then the tap is cooled with kerosene; if a thread is being cut on a copper part, then with turpentine; when cutting a steel thread, it is best to cool the tap with an emulsion.

Source: https://samastroyka.ru/narezanie-rezby-metchikom.html

How to properly cut a thread with a tap video

First of all, you need to choose the right tool. The range of all kinds of cutting devices is quite wide - these are grinding wheels, cutters, files, taps, dies and others. Often both specialists and folk craftsmen easily use many of them, while not everyone knows how to cut threads.

When making a nut or in any other case where an internal thread is required, taps are used. The appearance of the tap quite expectedly resembles a screw - that’s right, it is the screw that is screwed into the nut!

But in this case, this “screw” is turned into a cutting tool. Taps are made from hard tool steel, and the cutting edges are quite sharp. If the tap is worn out, with traces of corrosion or worn out cutting edges, then it will not be possible to cut a good thread.

The top of the tap has the shape of a cone - this makes it easier to center the tool during the thread cutting process, and on the sides there are special grooves into which the resulting chips fall. It must be said that there are also “grooveless” taps.

Taps are produced by hand and machine. An important difference between a hand tool is that the tap does not cut the workpiece to the full depth of the profile, but divides it into parts. Therefore, there are several taps for the size of one thread, and they differ in the number of annular grooves applied to the “tail” of the tool (respectively, number one, number two, etc.) There is also a special “roughing” tap, which is marked with an annular rim.

How to cut threads correctly

First, determine the diameter of the thread. Here it is necessary to take into account the thread pitch length. If M20x1 is required (diameter 20, thread pitch 1), then the internal diameter of the future nut will be 19 mm.

The hole for the thread in the workpiece can be made using a drill. The drill must be directed only perpendicular to the surface, otherwise the workpiece will be hopelessly damaged.

The first step is rough thread cutting, for which an appropriate tool is used, then all other stages of work are carried out. The tap is secured using a special wrench, but in extreme cases, an adjustable wrench will do.

Important Notes

• You should work with taps carefully - hard steels, as a rule, are characterized by increased fragility, so there is a risk of tool breakage. In any case, it is advisable to have spare taps.
• Thread cutting is carried out using the entire set of taps sequentially. If you skip at least one stage in a hurry, you won’t get high-quality carving.
• When working with non-ferrous alloys (copper, tin or aluminum), it is necessary to periodically unscrew the tap and remove chips.
• Ferrous metal shavings are removed by turning the tool in reverse.
• To reduce friction, you can use turpentine, kerosene or linseed oil. No need to use lubricant when working with cast iron and bronze.
• During work, periodically check the position of the cutting tool in relation to the workpiece - the tap should only be at a right angle to the surface.
• If the thread is cut in a blind hole, then the depth of the hole itself should be slightly greater than the depth of the threaded part.

It must be remembered that if the working rules are violated, a good thread will not be obtained, and the tap may break during operation. Removing a cutter fragment can be problematic; in addition, the workpiece may be completely damaged.

To obtain a good result, skill is always required, so if the work is being done for the first time, it is advisable to stock up on several blanks for threading. It is better to first learn in practice how to properly cut a thread with a tap. A certain number of initially damaged samples will ensure reliable operation in the future.

Source: https://crast.ru/instrumenty/kak-pravilno-narezat-rezbu-metchikom-video

Taps for threading: size table and standards for threaded connections

It’s hard to imagine, but threaded parts existed back in Ancient Greece and Rome. Such artifacts were produced by hand on primitive lathes or in forges. Often a nut from one pair did not fit a bolt from another pair, which caused a lot of inconvenience.

In the middle of the 15th-16th century. a special cutting tool appeared - a tap. It allows you to quickly obtain internal threads with a high degree of accuracy.

Design

Manufacturers are constantly improving their range of taps, optimizing their geometry for new materials and processing conditions. But the basic rod-shaped design remains unchanged. In the photo of the taps you can see a number of standard solutions, including the shank, working part, and grooves.

Each of them has its own purpose:

The grooves form cutting edges, remove chips, and facilitate the supply of coolant. They are oriented rectilinearly or along a helical line. Taps with left-handed helical recesses are used for through-threading. Blind holes are made with right-handed screws. The number of grooves varies in the range of 2-6 pcs.

The intake (cutting) part performs the main work when shaping the thread, cutting off the allowance. It has a 3-20 degree cone, which helps the teeth cut into the material better.

The gauge section guides the tap, prevents the hole from breaking, and cleans the threads. To reduce friction, it is made with a reverse reduction in diameter to 0.1 mm.

Application

According to the shape of the threaded hole, cylindrical and conical threading tools are distinguished. According to the scope of application, it is customary to distinguish machine, nut and hand taps.

Manual

Indispensable when carrying out locksmith operations at home and at work. A square is milled on the shank into which the knob is installed. Tap sets contain roughing, intermediate and finishing tools, marked 1, 2, 3 respectively.

Machine-manual

Used on milling, turning, drilling and CNC machines. They are distinguished from manual ones by their short fence part and the ability to withstand heavy loads.

Nuts

The main area of ​​application is the formation of threads in nuts. Thanks to the special design, the parts are not screwed off the tap, but fall onto its long, straight shank. After completing the operation and removing the tap, the finished nuts are stored in containers.

Taps with curved shanks are installed on thread-cutting machines. During operation, the nuts accumulate on the shank and, under the pressure of each other, fall into the receiver or container.

Design

There are several dozen designs of taps for thread cutting. Each is adapted to a specific production task. According to this classification, the following types are distinguished:

• Grooveless. Used for aluminum and its alloys.
• With staggered teeth. In this way, friction is reduced when processing viscous materials.
• Stepped. The tool is conventionally divided into 2 sections, one of which carries out cutting, and the other smoothes.
• Combined. The most common option is a tap drill or a broach tap.
• With a channel for coolant supply. This increases labor productivity and the life of the tap.
• Bells. Allows you to obtain threads with a diameter from 50 to 400 mm. The number of feathers reaches 16 pieces.

Type of thread to be cut

For each type of thread, use a different tap. Based on this feature, the following varieties are distinguished:

• Metric, M is included in the designation. The dimensions of the taps must comply with GOST 3266.
• Inch conical. The unit of measurement for diameter is the English inch, equal to 25.4 mm. Instead of a pitch, write down the number of threads (turns) per 1”. The larger it is, the finer the thread pitch.
• Pipe cylindrical. They are designated by the letter G, followed by a number corresponding to the bore diameter. The thread pitch of taps is measured in threads per inch.
• Pipe conical, marked with the symbol R or Rc. The thread is cut on the surface with a taper of 1:16. The thread is cut all the way.

Material

Inexpensive low-carbon steel grades U10A and U12A are used as blanks for the manufacture of hand taps. This is due to the fact that the tool operates at low speeds with little heat.

Machine taps operating in harsh conditions with forced cooling are produced from high-speed cutters R6M5, R18 and hard alloys based on tungsten, molybdenum and cobalt.

Photos of taps for thread cutting

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Source: https://instrumentgid.ru/metchiki-dlya-narezaniya-rezby/

Tapping a thread on a pipe

[How to cut a thread] is a pressing question, because... this is the main method for connecting structural elements.

This can be done manually using a special device.

External and internal cutting of the part is separated, thanks to which the thread can be installed in holes of different types.

 The cutting method depends on the type of material you will be working with.

You will find the features of the process, as well as a description of the tools that are needed for this, in the article, and the video will help you cope with the task.

Tapping tap

A tap is a metalworking and turning cutting device made in the form of a rod with a cutting element mounted on it.

The cutter is used to create internal threads in various metal parts, pipes, and it can also be used to restore previously damaged threads.

The cutter has a working part and a tail part. The working part includes two sections: for cutting and for calibration.

The cutting section is usually cone-shaped and is responsible for direct thread cutting.

In this area, cutting teeth are also installed, which cover the area along the entire circumference. The calibration section is responsible for the final formation of the part.

It looks like a cylinder equipped with teeth, and continues as a cutting area.

It is longer, and its working element is divided by grooves needed to create cutters and remove chips.

The number of grooves depends on the size of the tap with the clamp - in devices not exceeding 22 mm, there are usually three of them. There are also special taps that do not have grooves.

In those devices where they are, the grooves can be straight or helical.

The back of the tap has a cylindrical shape, at the end there is a square, which is necessary for the possibility of fixing to the fastening tool.

This part of the tap is responsible for attaching the device to the hand holder or machine chuck.

Taps with clamps come in two types: manual or machine. Hand-held devices attach to hand-held holders and are designed to create internal threads.

Machine tools are installed on chuck holders of lathes.

Before you learn how to cut a thread with a tap, you need to decide on its type. The threads that can be made may vary depending on the type of device.

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The most common form of thread is metric - it is made using a metric tool.

To create threads on the inside of a water pipe, as well as in a heating pipe, specialized pipe taps are used; they can also be used to make reinforced threads in metal parts, and not just in heating elements.

To create a tapered or inch thread, you need to use a special inch tap, which allows you to make threads of the smallest size.

Most often you can find durable steel devices with a clamp - they are the most efficient, strong and durable.

In addition to the type of thread, taps differ in design: they can be single or complete.

The latter are used to create threads in several passes. Typically, the kit includes two taps, one of which is called finishing, and the second is called rough.

In some cases, a tap is added here for medium processing. The number of parts in the kit is always indicated on the back, on the tail part.

The complete taps are not the same; they have different tooth shapes: the rough tap has the shape of a trapezoidal tooth, the middle tap has a triangular shape with a rounded apex, and the finishing tap has a standard triangle with a sharp tip.

Threading involves creating a protrusion in a hole, and the protrusion line should have a helical shape.

The protrusion near the wall in the hole must meet the specified parameters in order for the thread to be used: it must have the correct pitch, lifting angle, outer and inner diameter, etc.

Another important parameter is the depth, which is determined based on the diameter of the threads inside and outside the pipe.

There may be several options for how to cut a thread correctly.

The direction of the thread in the pipe can be different, depending on the need: it can be directed to the right, in which case the protrusion develops clockwise, or it can be left-directed, in which case the protrusion will follow counterclockwise.

There are two possible profile shapes: rectangular or triangular, as well as special additional shapes, but they are used mainly in production, and almost never at home.

Tap selection and cutting

A tap is selected depending on the thread that is needed, as well as its purpose (the thread may differ in profile shape, thread pitch, tolerances).

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To select a tap, there is a table that shows the accuracy classes - in accordance with them, you need to choose what type of tap to purchase - a set or a single tool.

An important factor to consider when choosing a tap is the required accuracy of profile cutting.

Different tools have different finishes on the cutting element, and this also needs to be taken into account.

The metal you will be working with will directly affect the tap you will need for it.

On aluminum, a sharpening angle of at least 25 degrees will be required, on cast iron and copper up to 5 degrees will be enough, and on steel – up to 10 degrees.

For the manufacture of the tap itself, ordinary or high-strength steel is most often used. When choosing, you need to focus on the diameter of the hole in which the thread will be made.

Before creating threads in aluminum, cast iron or other metal parts, you need to make a hole. It can be through or blind, depending on the need.

The hole can have any diameter, it is only important that it be smaller than the future cutting. It is best to choose a drill bit for the hole based on the thread size.

There is a special table that shows the recommended drill diameter in accordance with the thread size; it is recommended that you familiarize yourself with it before starting work.

If you need to make a large wall thread on cast iron or aluminum, then you should choose the diameter for the hole by multiplying the thread diameter by 0.8, so you will get a value that will be closest to the required size.

Creating a hole for an internal thread is not done manually, but using a special drilling machine or electric drill.

If using a drill, the workpiece must first be clamped in a vice so that the drilling location is exactly where it is needed.

When drilling, the drill must be positioned strictly vertically and not deviate from the specified plane.

To make it easier to work with a tap, you can chamfer the top edge - then the device will fit easier.

IMPORTANT TO KNOW: How is sheet metal bending carried out?

This can be done using a drill with a larger diameter or a file. After finishing the work, the hole must be cleared of chips.

This must be done especially carefully in a blind hole, otherwise cutting will not work well.

Before drilling, the part you will be working with must be firmly secured with a vice, with the chamfer on top, and the axis of the hole you made must be perpendicular to the table.

The tap must be fixed into the socket of the driver, and then inserted into the chamfer of the workpiece hole. The device is always inserted vertically.

After this, you need to press the tap firmly against the workpiece (preferably with both hands) and begin to rotate it clockwise.

Sudden movements or stops should not be allowed: the device must be rotated slowly and evenly, but at the same time work with pressure.

You need to work with the tap in the following sequence: first two turns forward, then half a turn back and then forward again. This method involves processing the entire hole in the pipe.

The tap needs to be cooled from time to time while cutting.

Different cooling methods are used for different metals: kerosene will be effective for aluminum, turpentine will be effective for copper, a special emulsion will be effective for other metals, and when cutting in cast iron, cooling the device is not required.

For internal threading, it is best to use tap sets.

The work is as follows: first you need to make a rough thread, then use a medium tap, which is passed through the hole, and then the final cut is formed using a finishing tap.

This sequence is optimal for the best processing quality, so it is recommended not to skip any of the three devices, otherwise the quality of the thread in the pipe will be noticeably worse.

You can see all the stages of the cutting process in the video - there is nothing complicated in this process, the most important thing is to choose the right diameter and follow the sequence of work, and also remember how to work with this or that type of metal.

In this case, you will receive high-quality threads in the pipe, which can be used to connect any parts.

Source: https://rezhemmetall.ru/kak-narezat-rezbu-metchikom-na-trube.html

How to properly cut threads with dies and taps - instructions

Often, when performing home repairs, it becomes necessary to make threads - external or internal. In order not to involve specialists in this, but to do it yourself, you need to purchase a special tool. Cutting with dies and taps does not require any special skills or abilities. It is enough to know their types and technical parameters.

How to cut a thread manually with a tap - SEO promotion from Anatoly Kuznetsov

The thing is that the scope of application of taps, in this case, turns out to be very diverse. For example, the need for them may arise to restore carvings in household appliances, on a bicycle, or to attach elk antlers to the wall.

Let’s say right away that there are a great many taps, some are used relatively often, others extremely rarely, so in order to be able to choose the right tap for yourself and be able to cut threads with it correctly, we have prepared this story. So here we go:

Types of taps for threading

Let us note once again that these are the most common; other types are used only for highly specialized work.

Let's start with the most common ones.

Metric taps for thread cutting

This is the most widespread group of taps, it includes: machine-manual (m/r), manual, wrench and left-handed. All of them may be in demand to one degree or another.

Machine-hand taps for threading

According to GOST 3266-81, m/r are produced starting from a diameter of 1.0 mm and up to 125.0 mm. Of course, such extremes are definitely not useful to us; mainly those with a diameter from 4 mm to 24 mm are in use.

Their distinctive feature is the presence of a neck (recess) on the shank; it is needed for reliable clamping in industrial machines. In addition, they also come in different designs, but for you and me all this will not be important, we will still use them as manual ones.

These taps are produced in 2 versions: complete and single-pass.

Complete taps

1) Complete ones always consist of two taps, each of which has its own purpose and name, rough (No. 1) and finishing (No. 2). Thread cutting begins with the first number, and is completed with the second.

The kits are considered the most expensive, so it is best to use them in hard steels or to obtain particularly high-quality threads.

Single pass taps

2) Single ones, in turn, are available for blind and through holes, here I think everything is clear from the name.

They cut threads in one pass, i.e. They are essentially universal, hence their pros and cons. The process of cutting threads will be more difficult, you may have to go back and forth with a tap more than once to get what you need, but they are not expensive.

Hand taps

This type is also designed for cutting internal threads in metal only manually - using a special wrench. They differ from m/r in the absence of a groove, length and inability to work in tough and difficult-to-cut steels.

They only come as complete sets, despite this, they often cost much less than single m/r ones, because their “quick-cut” material turns out to be of lower quality. They are often made from U7 carbon steel. In general, their only advantage is in price; if you have to process a non-hard material or you just need to drive a thread, they are quite suitable. In other cases, depending on your luck.

Nut taps

You will not confuse these taps with any others, because they have an elongated shank. They are intended to work in automatic machines for the production of nuts, but this does not prevent them from being successfully used for our purposes. Sometimes there are situations when the working length of a conventional tool is not enough, and this is where these come in handy.

They are always single and cut threads in one pass.

Left taps

They are produced only in machine-manual sets, which does not prevent them from being used as manual ones. Although they have a narrow scope of application, the need for them arises regularly. This could be the repair of some tricky imported equipment or car, or simply as an extractor.

Each number (1 and 2) has additional markings in the form of the Russian letter L or the Latin LH, indicating that it is intended for cutting left-hand threads.

We’ve sorted out the types of metric taps, now we’ll tell you how to choose the right size.

All of the above types must be labeled. It can be applied in different ways, but this does not change the essence of the matter and does not determine the quality of the product. The following must be indicated: diameter, thread pitch and type of high-speed material.

Examples:

— M10x1.25 HSS

— М12х0.75 Р6М5

For each diameter, GOST defines its own list of thread pitches. Each d also has a so-called main pitch, for example, for 6 mm it will be 1.0, for 10 mm it will be 1.5, for 16 mm it will be 2.0, in this case it may not be indicated on the tool. It will have the following markings: M6, M10, M16, respectively.

Let us note one more feature - the thread pitch in numerical terms cannot be higher than the main one. Example: an M14 mm tap has an o/w of 2.0, which means it cannot have a pitch of 2.5 or more.

Which tap for threading is better to buy?

The easiest way is to measure a stud or bolt that has been or will be screwed into the part. We measure the diameter with a tangent caliper (SC), and the thread pitch with a metric thread gauge.

If there is neither one nor the other, we take the part to the tool store, where they will do it all for you. Of course, a situation is possible when it cannot be removed or it weighs a lot, in which case you will still have to purchase a thread gauge. However, keep in mind that they come in metric (M60) and inch (D55).

Now a few words about good and bad taps. Many people tend to divide this tool into professional and ordinary. It is customary to classify the first as expensive products from famous European companies, and the second as those made in China, but this is not entirely correct. Perhaps some pattern can be traced, but in general the situation looks a little different.

When purchasing, it is better to adhere to the following recommendations:

• if you only need to renew the thread or cut it in a non-hard material, then the cheapest hand tap will do,
• for critical work, we choose complete equipment produced in Ukraine (Vinnitsa, Lvov) or joint Russia-China (TulaMash, Inreko, Belgorod),
• the best in terms of price-quality ratio are taps produced in the USSR,
• the P6M5 marking applied to the tap does not guarantee its quality (applies to cheap products),
• The best performance is achieved by taps marked P9, P12, P18, P6AM5, P6M5K5.

And also, when purchasing a thread-cutting tool, do not forget to take a special wrench for it.

Taps cannot be classified as a constantly used tool, but in some cases you simply cannot do without them, so we hope that this article will help you better understand this issue.

We have not touched on another interesting group of taps - inch ones, but they are used much less frequently than the above and we will talk about them in another article.

Source: https://hozyindachi.ru/kak-narezat-rezbu-metchikom-vruchnuyu/