27/10/2025
During the production of spear bolts...
As the core fastening component in shield tunnel engineering, segment connecting bolts are key carriers for splicing tunnel segments, achieving sealing and waterproofing, and transmitting structural stress. They are even more the "lifeline connectors" that ensure the overall stability and long-term safe operation of tunnels, laying a solid foundation for underground transportation arteries.
High-carbon steel or alloy steel (such as 45 steel / 40Cr) is selected as the material, and stainless steel is used in special working conditions. The products are processed through precision technologies such as quenching and tempering heat treatment and thread rolling forming. The products have excellent tensile strength, fatigue resistance and corrosion resistance, and can withstand the long-term erosion of harsh environments such as high underground humidity, continuous vibration and soil stress, ensuring stable and reliable performance.
Specifications and models are customized on demand. Common diameters include T25/T28, and the length can be flexibly adapted according to the thickness of the segments. The combined connection method of "bolt + matching threaded sleeve + metal washer + nylon washer" is adopted to ensure long-term fastening without loosening structurally. The products are produced in strict accordance with ISO 898 and other rail transit industry standards. They are easy and efficient to install, with excellent sealing performance, and can effectively disperse structural loads, prevent segment displacement and leakage. They are suitable for the splicing needs of shield tunnels with different diameters such as subways and river-crossing tunnels, providing core guarantee for the safety and long-term operation of tunnel structures.
