CNC thread machining

CNC thread machining is an efficient thread machining method, which uses CNC technology to control the machine tool for thread cutting or rolling.

The main function of the thread is to connect two parts so that they can operate freely. CNC thread machining usually involves several structural elements, including the tip of the tooth, the root of the tooth, the spiral Angle, the pitch and the side.

Different types of thread processing, threads can be classified according to a variety of classification schemes, so a variety of different types of threads are produced.

External threads: External threads are commonly used in parts such as bolts, screws, studs and plug gauges. These threads can be efficiently machined by lathe or cut manually using a circular die tool. In addition, there are hexagonal and square molds designed specifically for specific applications.

Internal thread: The internal thread is the thread that is machined inside the material and is usually cut by using a single-lip thread tool. Traditional thread caps and single-lip tools can also be used for machining CNC internal threads. It should be noted that the internal thread can only be cut on the concave surface, and if the workpiece design needs to insert screws, the internal thread must be machined.

The advantages of CNC thread machining include: surface roughness is less than turning, milling and grinding; The surface of the thread after rolling can improve the strength and hardness by cold hardening; High material utilization rate; The productivity increases exponentially compared to the cutting process, and it is easy to automate; The rolling die has a long life. However, this processing method also has its limitations, requiring high dimensional accuracy of the blank; The precision and hardness of the rolling mold are also high, and it is difficult to manufacture the mold; Not suitable for rolling threads with asymmetrical teeth.

Classification and characteristics of tap processing

The use of tap machining thread holes is the most commonly used processing method, it is mainly suitable for small diameter (D<30), hole position accuracy requirements are not high thread holes.

Most of the technical masters in the earliest period used flexible tapping methods to do it, but the flexible tapping chuck has a complex structure, high cost, easy damage, and low processing efficiency. In recent years, the technology of cnc machining has gradually improved, and the rigid tapping function has become the basic configuration of cnc machining.

Therefore, rigid tapping gradually became the main method of thread processing (rigid spring chuck grip tap, spindle feed and spindle speed is controlled by the machine tool to maintain consistency).

Compared with the flexible tapping chuck, the spring chuck has the advantages of simple structure, cheap price and wide use. In addition to clamping taps, it can also hold endmills, drills and other tools, which can reduce the tool cost. At the same time, the use of rigid tapping can be high-speed cutting, improve the efficiency of processing, and reduce manufacturing costs.