How to properly thread a pipe
Varieties and features of clips
There are mechanical and electric tools for threading. Companies that make clubs come with a set of interchangeable heads. One-time threading is possible with a head of the required diameter, bought as a single piece. This threading is done with a gas or adjustable wrench. its jaws grasp the 4 lugs on the cylindrical reamer.
Hand tools equipped with a special reverse ratchet have a small turning angle of the handle. This is handy for work in hard-to-reach places. ratchets differ in the number of teeth. the more of them, the smaller the angle to which the handle will turn. You can also use a standard ratchet holder instead of a ratchet, which has a reamer mount and threaded sockets designed to hold rotary knobs. The handles can also be used in place of the ratchet to turn the head if the diameters of the ratchet and the turner are the same. In this case, the lathe is fixed by the fastening bolts. This option is not suitable for hard-to-reach places due to the latitude of the rotary movements.
The electric coupling is designed for cutting long pipe sections or large pipe threads. The tool comes complete with four or more sockets and a clamping base for securing the drive unit. The reamer is designed as a tablet with a socket. Number of facets on the socket may vary. With this device you can thread a short pipe without using a clamp and without chamfering the pipe. with inverted combs. But before you thread a short pipe with the tongs, you always need to apply a few drops of oil to the end of the pipe.
Threading a pipe against the wall
If the workpiece is located in a place where there is no space to approach and carry out the operation, we offer several ways to minimize the financial costs that are sure to arise in a non-standard situation:
If it is possible to remove a small section of the wall, such as a ceramic tile, take advantage of this. That gives you a lot of room for the task at hand.
- A pipe consists of several parts. You have to disassemble the line and cut it on the removed section.
- As we wrote above, cutters need constant lubrication. However, oil from a horizontal surface runs off. This is why it is advisable to work in several passes to achieve a perfect surface finish.
- Keep the tool parallel to the axis and apply a sufficient load.
It’s not enough to cut a thread with a hand saw alone. You also need an auxiliary device to clamp and hold the body of the die. a die holder.
One tool is designed for several thread sizes at once. for small, medium and large threads. Place the strip inside the holder and secure it with the screw.
Types and features
The task of threading a pipe with a die is realized quite simply, if the part is selected appropriately. There are several kinds of dies:
- Metric. Measurement of parts in millimeters, the profile in the form of a triangle with equal sides, a smaller step.
- Thumbnail. Measured in inches, the profile type is an isosceles triangle, the pitch is larger. Due to the large profile, reliable threads are obtained.
Inch dies are suitable for threading in water pipes, and metric dies are suitable for fasteners. Threads are also divided into left and right. What it means?
The right-hand thread is characterized by turning the nut clockwise, and the left-hand thread is characterized by turning the bolt in the opposite direction. For quality threading and reliable connection, the rod must be 0.2-0.3 mm smaller than the external dimensions of the thread.
Preparing for work
First you need to find and if necessary cut with an angle grinder or metal saw a suitable piece of pipe. When cutting, you must make sure that the cut is strictly perpendicular to the planes of its walls.
immediately before tapping, the surface of the pipe should be cleaned of rust or old paint and other foreign substances, using sandpaper and a file. In addition, a chamfer should be removed from the end of the pipe with a file to make threading easier. Now let’s proceed to the preparation for threading.
- The diameter of the pipe does not match the diameter of the thread;
- use of improperly centered, rusted or blunt tools
- working without lubricating the tool and pipe will cause the threads to crack or break;
- excessive physical effort due to a complete lack of experience can cause the thread to break off.
How to thread male threads with a die
A special tool with dies of various diameters is used for cutting male threads by hand.
Tap holder with dies for different diameters
At hard to reach places, e.g. near walls, a ratchet tool is used.
The nominal diameter of the thread is the diameter at the apexes of the thread triangles. The die cuts the metal, forming hollows and leaving the tops untouched, so both the stem and the die must be the same diameter. The thread diameter, for example, M3 is M metric thread, and the number is the nominal thread diameter in mm. If you thread 3 mm rods, you take an M3 strip, and then use a ratchet. Core is measured with caliper.
A chamfer shall be cut off from the face of the rod to make the die cut better.
Principle of cutting with a dies
A vise is needed to clamp the workpiece. The workpiece is firmly clamped in a vice and oiled with machine oil to make the die run easier, reduce friction and tool wear.
when threading with a die, large accumulation of chips in the chamfer holes must be avoided.
Place the facing piece perpendicularly to the workpiece. With a little pressure, start turning the tool holder clockwise if the thread is right-handed, respectively, if left-handed, counterclockwise.
- First make 2-3 turns.
- Then half a turn back to remove swarf.
- Apply lubricant after every 3-4 turns, possibly with a syringe.
- And so.д.
Threads are checked with a nut or caliper ring. Nuts for your threads can be purchased here → https://rus-metiz.com/categories/gaiki (RusMetiz).
Peculiarity of threading on pipes
There are 3 types of pipe threading: on a lathe, with a die or a pipe tong. In practice, the most common thread is of the triangular type:
- inch, with measuring calculations in inches. The thread is characterized by high strength due to the large pitch and large profile. Used for water pipes;
- Metric, measured in millimeters, used for pipe fasteners.
The cluppe is a tool with limited functionality and is only used for cutting pipe threads. On lathes, the process is structured as follows: the tube is fixed in the spindle, then the cutting cutter removes all excess, selects the appropriate pitch and applies the thread.
Pipe cutting in the home and private workshops can be done with improvised tools.
One of such is a pipe tongs, before using which it is worth carefully preparing.
In places where threading is planned, any kind of dirt and rust must be completely removed. This will improve the quality of the coils and prevent premature oxidation of the material.
If there is a chamfer on the tube, it must be removed. This can be done using a file or an angle grinder. However, in the second case, the quality of the chamfer may decrease.
It is necessary to lubricate the surface with oil before the work is done. This is the only way to achieve a smooth running of the mechanism.
if you ignore these recommendations, the thread quality can worsen and the working part of the tongs can wear out quickly. In addition, in some cases, it is also possible to break the pipe.
Manufacturers produce different types of clips for shaping threads. All products differ in size, design and main characteristics.
Therefore, when choosing a suitable tool, it is worth taking into account a number of features:
It is not necessary to use expensive models, if you plan to cut pipes at home;
It is not recommended to give preference to the cheapest ones either, because they will quickly fail and are suitable for one-time use only;
when buying should pay attention to the size of the clipper and the shape of the removable cutters;
the best option would be sets of working heads with different diameters, which simplifies the cutting;
DEMO: How to Thread Steel Pipe
Working part should be made of alloyed steel, treated with corrosion-resistant compositions.
Responsible approach to preparation will help to improve quality of the work and to achieve the desired result with the help of properly selected tools.