With what and how to perform threading on pipes?

Threading. one of the main types of fastening of metal pipes, which can be reproduced by yourself. So, below we will consider what tool is worth buying for threading pipes, and how to use it. But before this, it is worth determining the basic concepts, without which the performance of work will be impossible.

When installing a stop valve, transition tee or coupling on a metal pipe, a thread is necessarily made, which is characterized by the following parameters:

  • Depth. the distance from the base of the thread to the end of the pipe.
  • The profile and its angle. the cross-section at the coil, which is made in the form of a triangle, rectangle and other forms. When the side faces of the coils intersect, an angle is formed.
  • Pitch. the distance that is formed between the tops of the pipe or nearby coils.

Important: The greater the pitch, the greater the depth and the number of turns per 1 unit. threads and, therefore, vice versa.

With the definition of the profile and pitch should be treated with the utmost attention, because the type of thread depends on it:

  • Inch. appears as a triangle and is used in the assembly of elements of a water pipe, and sometimes. heating pipe.
  • Cylindrical. a variant of an inch thread that has a smaller pitch. The smoothed upper edge of the profile resembles a cylinder. An example of a diagram of the external cylindrical thread is shown below:
  • Conical. the type allows you to get a tight connection, which is especially important when using sealing materials.
  • Metric. kind used for small pipe diameters. Can be trapezoidal. the outer angle is made 30 degrees, and the sides of the coils resemble a trapezoid. For bolt connections, rectangular threads can also be used, because it makes the fixation more reliable. Here is a scheme of metric threads, which has the form of an equilateral triangle:

Preparing for the job

First, you need to pick up and if necessary cut with an angle grinder or metal saw a suitable piece of pipe. When cutting off need to control that the cut was strictly perpendicular to the planes of its walls.

Immediately before threading, the surface of the pipe should be cleaned of rust or old paint, other foreign deposits with sandpaper and a file. In addition, you need to remove the chamfer from the end of the pipe with a file to make the threading easier. Now let’s move on to preparing for threading.

The main mistakes when threading

  • the diameter of the pipe does not match the diameter of the thread;
  • use of improperly centered, rusted or blunt tools
  • Threading without oiling the tool and pipe will cause cracks or breaks in the threads;
  • excessive physical force resulting from lack of skills can cause thread breaks.

Required tools

Self-tapping pipe threading requires the following construction tools to be prepared:

  • machine oil, emulsion or kerosene
  • silicone gaskets
  • angle grinder
  • file
  • gas wrench
  • gloves, face shield, or goggles
  • rags

Manual threading tongs and a set of dies

technology features

The following algorithm can be used for tapping internal threads.

thread, pipe, internally
  • In the place on the surface of the workpiece, where the hole will be drilled for thread cutting, it is necessary to form a recess for a more accurate approach drill, using a core and an ordinary hammer. Insert the drill bit into the chuck of an electric drill or a drilling machine, and let it rotate at a slow speed. Before you start drilling, the cutting part of the drill bit must be treated with a lubricant: the lubricated tool enters more easily into the structure of the processed material and creates less friction in the machining area. The drill bit can be lubricated with a piece of ordinary lard or solidol, or if viscous materials are involved, machine oil should be used for this purpose.
  • If small parts are to be threaded, they must be clamped in advance using a bench vice. When drilling, the tool, fixed in the chuck of the equipment, should be placed strictly perpendicular to the surface of the workpiece. The tap should be regularly lubricated, and you should make sure that it does not twist and moves strictly in a given direction.
  • At the entrance to the hole, as mentioned above, you must remove the chamfer, the depth of which should be 0.5-1 mm (depending on the diameter of the hole). A larger-diameter drill bit or countersink can be used for this purpose by installing them in the chuck of the drilling equipment.
  • The thread-cutting process begins with the tap. which is first inserted into the screwdriver. Do not forget about the grease that must necessarily be applied to the thread tap. The position of the tap in relation to the hole to be tapped must be set at the very beginning of the work, because later, when the tool is already inside the hole, it will not be possible to do so. When threading with a tap, the following rule must be followed: 2 turns of the tap should be in the progress of threading, 1 against the progress of threading. When the tap is made one turn backwards, chips are removed from its cutting part and the load on it is reduced. Threading with a tap is performed according to the same method.
  • After threading with a tap, the tool is installed in a screwdriver, and after it. Handling them is carried out by the method described above. When threading with taps and dies, you must feel when the tool begins to rotate with force. As soon as you reach this point, you should turn the screwdriver in the opposite direction to eject the chips from the cutting part of the tool.

The harder the material, the more you need to lubricate the tap while threading

Before tapping or threading external surfaces with a tap, you must learn the procedures well and strictly follow the rules. Only then can you expect to be satisfied with the quality and precision of your work.

Process organization requirements

For threading to be successful, it is important to follow the basic requirements:

  • First carefully clean all dirt and dust from the surface,
  • Next, the surface of the working tool and the workpiece to be treated should be lubricated with a special fluid,
  • Check that the tool is in good condition before beginning work.

At the warehouse of Minsk wholesale and retail metal warehouse “Aksvil” you can choose and buy any steel pipes you need for construction or plumbing works:

Thread cutting with a manual clevis

Threading pipe makes it easier to use the tongs with the ratchet and guide. Use this procedure.

  • Set the clevis in the ratchet.
  • Oil the cutting part of the power tongs.
  • Install a pipe end guide on the end of the pipe to be tapped.
  • Rotate the ratchet around its axis while tapping.
  • Add oil from time to time to make the tool stroke easier.

The cutting part of the tool can become blunt after prolonged use, so it is necessary to observe the condition of the tool and periodically resharpen it.

Using a handheld cluppet for tapping


How to thread a pipe yourself?

thread, pipe, internally

Self-tapping threading begins with a number of preparatory steps:

  • Cutting a piece of pipe to size. When replacing a damaged section of the pipeline, the first thing to do is to carefully cut it out in a strictly perpendicular direction to the wall. If this condition is not met.
  • Cleaning the threading area. All the paint and corrosion must be removed completely from where the pipe threads are to be cut: if this is not done the work can be clearly hampered.
  • Chamfering. To make the job easier, a chamfer must be removed from the ends of the pipe.

How to thread a pipe internally?

A machine for threading pipes is unlikely to be needed for someone who is furnishing his home. It’s more of a working tool. In design, it somewhat resembles vertical drilling machines.

How to cut an internal thread in 3 steps by hand

The diameter of the workpiece to be tapped and the threading pitch is adjustable. The operation of the spindle can be carefully debugged by adjusting the number and speed of revolutions. In principle, such a machine does almost all the work. Also, unlike manual scales, the machine can make not only the external thread, but also the internal. modern machines can handle the smallest details and products with thin walls.

Above described in detail all the basic steps of the work, which you need to know both the beginner and the hardened master when threading. However, if you realize that you are not successful in this process, and you need to continue the repair, it is best to contact a professional trimmer.

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