JIS B 1186 F10T bolt set
The Friction grip bolt is a high-performance structural fastener designed for preloaded connections where the clamping force between connected steel members transfers shear loads through friction rather than bearing on the bolt shank. This connection method requires precise preload application to generate sufficient friction at the joint interface, ensuring that slip does not occur under service loads. Friction grip bolting is widely used in critical steel structures such as bridges, high-rise buildings, industrial plants, and wind turbine towers, where connection stiffness, fatigue resistance, and structural integrity are paramount. These bolts are typically tension-controlled using torque wrenches, turn-of-nut methods, or tension-control (TC) systems to achieve the specified preload.
A High strength bolt set is a complete fastening package that includes the bolt, nut, and hardened washer(s) — all manufactured to matched mechanical properties and dimensional tolerances to ensure optimal performance. These sets conform to recognized standards such as ASTM A325, A490, or EN 14399, covering diameters from 1/2"to 1-1/2"with tensile strengths up to 150 ksi (1034 MPa). The bolt, nut, and washers are designed to work together seamlessly, with the washers providing a hardened bearing surface to distribute clamping forces and prevent indentation of connected materials. Using a complete set from a single manufacturer eliminates compatibility issues and ensures that all components meet the required strength and hardness specifications.
The Hex bolt assembly features a standard heavy hexagon head that provides a large bearing surface and facilitates easy tightening with standard wrenches or power tools. The hex head design allows for positive engagement and precise torque application, essential for achieving the required preload in friction grip connections. These assemblies are available with various surface finishes including plain (black oxide), zinc-plated, hot-dip galvanized, and weathering steel (Type 3), providing options for different corrosion protection requirements. Hex bolt assemblies are widely used in structural steel fabrication, heavy machinery mounting, bridge construction, power transmission towers, and offshore platforms. Proper installation and inspection procedures, including verification of preload using calibrated tools or direct tension indicators, are essential to ensure the long-term reliability of these critical connections.
