Pipe lathe

What is a pipe lathe and why is it an important machine tool for machining these parts? Pipes can be machined in different ways and through different methods, but using a pipe lathe can be a great alternative for workshops with the most advanced technology.

What is a pipe lathe like?

Is there such a thing as a pipe lathe? You should know that pipes are apparently simple parts, but complex to manufacture. A pipe can come in different shapes and materials and with specific characteristics. Depending on the needs of the part, different machines can be used. For example, when you want to turn a sheet into a tube, it is enough to use plate bending rolls or a tube bender and even press brakes.

The process is simple and consists of deforming the sheet or metal plate to give it a curved shape. These processes, which do not involve swarf removal, are very simple and do not require specific machinery. But what happens if the pipe is more complex? Pipes can have specific features, such as threads. Those used to connect piping systems, for example, need to have a thread, which is a set of grooves (internal or external) that allow them to fit with other parts and form a complete assembly.

In these cases pipe lathes are used, or in other words, a lathe that can perform the cutting of threads. This cutting makes it possible to produce a uniform helical ridge on a workpiece. To make this thread, successive cuts must be made with a specific threading tool that has the shape to be created.

Why use a threading lathe?

The pipe threading lathe, or thread lathe, is a type of machine tool that makes it possible to machine different parts related to piping; that is, with them you can create not only the threads but also the different couplings, such as sleeves, for use on pipes. The most complex pipe lathe is the oilfield one, as it makes it possible to produce drill pipes and parts of large diameter and size.

It is true that conventional lathes can carry out different internal and external threading and straight turning operations. But if the machining workshop is dedicated to the manufacture of pipes, it is advisable to get a specific machine tool. The pipe lathe is characterised by being very efficient and able to produce large volumes of parts and, in addition, with great precision.

Threading lathe with CNC technology

You should know that some pipe lathes include computer numerical control (CNC) technology. These machines are very complex and allow the manufacture of parts with very specific machining needs. In addition, CNC is in itself a type of technology with its own benefits. A CNC machine provides greater efficiency and speed in machining, which shortens delivery times. In addition, a single operator can work on several CNC machines at the same time, which also reduces labour.

Finally, CNC machines, which operate through an alphanumeric language, incorporate a computer that, following prior design and configuration, determines all the machining parameters needed for the manufacture of pipes and threads. This technology has been adopted partially in threading lathes, as the CNC language has been shown to improve the efficiency and accuracy of all machining operations.

Features of the pipe lathe

What is a pipe lathe like? These machine tools generally have a large through bore in the spindle housing. To machine the part, it must be passed through this bore and clamped by two chucks placed at both ends of the spindle so that the part can rotate.

The size of the spindle bore can vary depending on the model of machine purchased. Some accept pipes of 135 mm, others up to 500 mm, which is the maximum swing diameter of the workpiece. For the part to be able to rotate, it is also placed on a base or bed that must be of the right size and proportionate to the dimensions of the spindle and the pipe. Some machines can work on parts with maximum lengths of 15,000 mm.

Although many of these machines work via CNC and it is the computer that sets the cutting parameters, it is advisable to make calculations so that the thread can have the required dimensions. Finally, it is advisable to cut the threads first and then make the cuts.

Parts of the pipe lathe

All machines can vary, but they usually have parts in common. These are:

• Spindle. It must have a large internal diameter. It determines the size of the pipe to be machined.
• Double chuck. This element is essential for properly holding the part. Each end of the pipe must be placed in a chuck.
• Integral bed. It is made of solid, sturdy iron, because it must be highly resistant to the vibrations produced by the machine.
• Guideways. A series of guideways are placed on the bed, and these must also be made of quality materials that are resistant to wear.
• Taper guide bar. Not all pipe lathes include this accessory. Thanks to it, it is possible to machine tapered threads.
• Automatic tool changer. The vast majority of CNC machines include this technology, which allows continuous machining without having to remove the part or stop production.