Our research group has been developing 1,700 MPa class ultra-high-strength bolts and will try to rationalize bolted connections with the bolts. This study conducted mass production of 1,700 MPa class bolts and confirmed the tensile resistance experimentally. The slip behaviour of friction type bolted joints with them was also investigated. The mass-produced bolts demonstrated the stable tensile resistance derived from the used material. Slip test results of double-lap joints coated with inorganic zinc-rich paint found that the slip coefficient evaluated by the bolt tension before the test was larger than 0.45, and the bolt tension reduction through the slippage became less than about 3 percent.
