232.96 tons of M30 Tunnel segment bolts supplier for Wuxi Metro Line 6
In 2025, Anyang Railway Equipment Co., Ltd. supplied 232.96 tons of 8.8 grade M30 Tunnel segment bolts to the Wuxi Metro Line 6 Section 07 project.
Wuxi Metro Line 6 is a north-south metro line located in Wuxi City, Jiangsu Province. It runs from Gonghu Wetland Park Station in the south to Guangtong Road Station in the north, with a total length of 24.26 km.
The China Communications Construction First Highway Engineering Bureau Group Co., Ltd.’s Wuxi Metro Line 6 Civil Engineering Construction Project Section 07 includes 3 stations, 2 sections, and 1 depot access line, namely the civil engineering and tunnel boring machine (TBM) works (excluding the production and transportation of concrete segments) involving the section from Taihu New City Station (inclusive) to Olympic Sports Center Station (inclusive) to Gonghu Wetland Park Station (inclusive) and the Gonghu Wetland Park depot access line.
In 2025, Anyang Railway Equipment Co., Ltd. supplied 232.96 tons of 8.8 grade M30 Tunnel segment bolts to the Wuxi Metro Line 6 Section 07 project.
The requirements for M30 tunnel segment bolts are as follows:
(1) Longitudinal bolts shall be M30 tunnel steel bolts, grade C, with a processing quantity of 28 bolts per ring and a mechanical performance grade of 8.8.
(2) Longitudinal nuts shall have a performance grade 8 and a pull-out force of not less than 350kN.
(3) Longitudinal bolt washers shall be steel washers, with a processing quantity of 56 washers per ring and a hardness grade of Hv=200.
(4) When machining the bolt threads, care must be taken to ensure a proper loose fit with the nut.
(5) All bolts and washers shall be coated with a zinc-based chromate coating and sealed, with a thickness of not less than 8.6um.
One set of metro sgement bolts includes 1 bolt, 2 nuts, and 2 flat washers.
The steel used for shield segment bolts, nuts, and washers shall comply with the following regulations:
(1) The ratio of the measured yield strength to the measured tensile strength of the steel shall not exceed 0.85.
(2) The steel shall have a distinct yield step, and the elongation shall not be less than 20%. (3) The steel should have good weldability and qualified impact toughness.
(4) The entire surface of the material should be coated with a chromium-free zinc-aluminum sheet anti-corrosion coating with a thickness of 5.9–8.1 μm.
