We don't know if you have doubts about how the inner thread of the wire thread insert is designed and produced under such a small diameter. Regardless of the difficulty of the process, it is already very difficult in terms of size. The key is the steel wire. The material of the screw sleeve is also not common, it is stainless steel with high hardness, which also increases the difficulty of processing and production. At the same time, the linear expansion coefficient of stainless steel is relatively large, which also means that as the temperature continues to rise, its internal deformation It may become bigger and bigger, which shows how difficult it is to process internal threads.
In addition, it is difficult for the coolant to enter the cutting area due to space problems, which is very bad for the cooling effect. If you are not careful, the tap will collapse or be "bitten" in the threaded hole, which is not worth the candle. When opening the hole, because the transition section of the blind hole is less than 2 times the pitch, the taper angle of the tap cutting is relatively large, and the cutting cone is short, so that the cutting load of the tap cutter teeth is large, and the tap is easy to break. It is easy to produce anti-cutting when returning, which will further cause chipping or breaking of the tap. Due to the compensation of the dimensional error of the steel wire sleeve profile, the precision of the thread is improved, and a special tolerance with high precision is given.
Although the wire thread insert is a very small part, of course there are also large ones, but the volume is generally small, but it is also a precision part, because its internal thread requires high technology in design and production, which is why a small The reason why the wire thread inserts are not cheap.