Four updates of China's thread standard parts:
1) In the 1950s, China formulated the mechanical industry standard for threading in accordance with Russian standards.
2) In the 1960s, China formulated a national standard for threading (improvement of industry standards).
3) In the 1980s, China revised the national standard for threads (new tolerance system) with reference to the ISO standard (the key technical parameters are consistent); the pipe thread was newly formulated.
4) From 2000 to 2004, China revised the national standard for thread according to the latest ISO standard (correspondence in the standard chapter). In order to promote the implementation of new standards and solve the difficult problem of finding foreign thread standard parts, in May 2004, the National Thread Standard Parts Committee and China Planning Press jointly published "Thread and Its Connection", and jointly published with the China Standard Press. , American and British thread standard parts manual.
Thread standard development trend
1. Establishment of the fastening thread inspection system: Improving the thread inspection level is the basis (discovery problem) and power (solving the problem) to improve the thread manufacturing level. Compared with foreign thread detection technology, there is a big gap in China. Establishing China's thread inspection system is a breakthrough to rapidly improve the level of thread processing in China.
2. Establishment of sealing thread inspection means: popularize the internal control parameter determination technology of sealing pipe thread, help enterprises to establish the quality control method of sealed pipe thread, and solve the leakage problem that has long plagued China's machinery industry.
3, thread anti-loose technology research: modern design puts more stringent requirements on thread relaxation, China should seriously study the advantages and disadvantages of various thread relaxation techniques, improve the reliability of threaded joints.
4, thread fatigue strength study: Russia, the United States and the United Kingdom have a more in-depth study of the relationship between thread individual parameters and threaded joint fatigue strength; China University of Aeronautics and Astronautics University using the theory of damage mechanics, can reproduce the generation of thread fatigue cracks on the computer Expansion process. The threading committee should pay attention to summarizing the relevant thread design principles and improve the design level (reliability and weight reduction) of threaded parts in China.
5, the full use of ISO thread standard parts: the basic standards should fully adopt the ISO standard to facilitate international trade.
6. ISO/TC1 Secretariat Work and the International Impact of China's Thread Standard Parts: Strive to undertake the ISO/TC1 Secretariat work and bring Chinese standards to the world. (Reprinted from HC Hardware Fastener Technology Column)
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