Threading

The production of threads is an essential part of the mechanical engineering industry, as threads are a crucial element in many machines and structures, providing a removable yet tight connection between parts. Threads can be produced using various methods, with the two most common being cutting and forming.

Thread Taps

Cutting thread taps are one of the most common tools for producing internal threads. In this method, a cutting thread tap cuts the thread into the hole. There are two main types of thread taps: bottoming taps and through taps.

A bottoming tap is equipped with a fluted chip channel, which allows the chips formed during the threading process to rise out of the hole. This feature makes bottoming taps an excellent choice for applications where the hole does not go through the part, making chip removal important. Through taps typically have a straight chip groove, which causes the chips to break into short pieces and exit through the through-hole. Thus, through taps are ideally suited for threading through holes.

Forming Thread Taps (Thread Forming)

Another common way to produce internal threads is by forming, also known as thread forming. The difference compared to the cutting method is that in thread forming, material is not removed, but a tool is used to mold the material into the desired shape, creating the thread in the hole. A thread hole produced by forming is high-quality in terms of both dimensions and surface finish. Additionally, a thread formed by this method is structurally stronger, and there are no issues with chip removal when using this technique.

Thread Milling

Thread milling is an efficient method for producing both external and internal threads. When using this method, one can choose between solid carbide or insert-equipped thread mills. Thread mills are particularly useful for handling large threads and hard materials. Thread milling also does not require much power from the machine, and the method allows for adjusting the thread size using the machining equipment.

Production of External Threads

There are several methods used in the production of external threads. Although high-speed steel thread cutting dies (thread packs) are one way to produce external threads, this method is mainly used today only for thread cleaning. The most common methods for producing external threads are thread turning and thread milling.

Thread Turning

Thread turning is a metalworking process that enables the creation of complex thread profiles by turning. This process is important for manufacturing various threaded parts such as screws, nuts, and bolts. Using specialized turning tools, thread turning allows for the precise and repeatable production of thread shapes, which is essential for many industrial applications. To ensure quality and precision, advanced CNC lathes provide automatic control and high repeatability. When the process is carefully managed, thread turning can produce parts that meet strict technical requirements, making it a crucial technique in modern manufacturing. In thread turning, a turning tool matching the thread profile processes the thread with a feed movement corresponding to the thread pitch. This method is particularly useful in thread production when precise dimensions and surface finish are required.