Recently, the International Organization for Standardization (ISO) and relevant institutions in China have been releasing updated information on standards in the field of self-tapping screws intensively, covering core requirements such as mechanical properties and testing methods for the two major categories of carbon steel and stainless steel. This series of standard upgrades not only promotes the alignment of industry technical norms with international standards, but also injects new impetus into the high-quality development of China's metal fastener industry.
In terms of domestic standards, the Standardization Administration of the People's Republic of China officially released GB/T 3096.5-2025 "Mechanical Properties of Fasteners - Part 5: Self-tapping Screws" on October 31. This standard will come into effect on February 1, 2026, and fully replace the 2016 version of the standard. According to the National Technical Committee for Fastener Standardization, the new national standard has been revised and adopted from the ISO 2702:2022 international standard. It has focused on optimizing key technical indicators such as core hardness and carburized layer depth, and added three core test procedures, further improving the quality control system.
At the international standard level, ISO 3506-4:2025 "Mechanical properties of corrosion-resistant stainless steel fasteners - Part 4: Tapped screws", which was launched by ISO in 2025, has also drawn industry attention. Compared with the old version in 2009, the new standard significantly expands the coverage of materials. For the first time, austenitic A8 steel and duplex steel D2-D8 are included in the specification. Moreover, the hardness testing requirements for HV5/HV10 are detailed for different thread sizes, and the applicable temperature range from -20℃ to 150℃ is clearly defined, providing technical basis for special environment applications.
The technological innovations brought about by the standard upgrade have shown results in the pilot projects of enterprises. Verification data from drafting units such as Zhejiang Xinshengda Metal Technology show that the one-time assembly success rate of self-tapping screws produced in accordance with the new standards has increased from 92% to 98%, the salt spray test corrosion resistance time has been extended from 240 hours to 500 hours, and the material utilization rate has also increased by 15%, achieving a dual improvement in performance and efficiency.
For China's fastener industry with an annual production capacity of over 8.5 million tons, this standard update is of great significance. Data shows that the annual output of self-tapping screws in China accounts for 15% of the total output of fasteners, but high-end products were long dependent on imports. Industry experts point out that after the implementation of the new standards, the technical trade barriers faced by China's self-tapping screw exports will be reduced by more than 30%. Meanwhile, the inclusion of duplex steel in ISO standards will promote domestic enterprises to make breakthroughs in high-end application fields such as new energy vehicles and aerospace.
At present, the China Machinery Productivity Promotion Center, in collaboration with leading enterprises in Zhejiang, Guangdong and other regions, has initiated the promotion and implementation of standards to assist enterprises in upgrading their production equipment and adjusting their processes. Many enterprises have stated that they are accelerating the implementation of the new standards. By introducing precise detection equipment and optimizing heat treatment processes, they ensure that their products meet the new requirements. With the improvement of the standard system, China's metal fastener industry will gradually transform from a "scale advantage" to a "quality advantage" and occupy a more core position in the global industrial chain.