Bolts M12 x 40 High Strength Friction Grip

High-Strength Friction Grip (HSFG) bolts are heavy-duty, high-tensile structural fasteners designed for preloaded steel connections.

When tightened to the specified preload, the bolt assembly clamps the connected steel plates firmly together. This allows loads to be transferred through friction between the contact surfaces, helping prevent movement or slipping within the joint.

How the HSFG Assembly Works

• Bolt: Manufactured from high-grade steel, commonly Grade 8.8 or 10.9, to withstand high tensile forces.
• Nut: Tightened using a controlled method to stretch the bolt and create the required clamping force.
• Washers: Hardened steel washers distribute the clamping load and help protect the connected steel surfaces during tightening.

Key Features and Benefits

• Slip-resistant connection: High clamping force creates friction between the steel contact surfaces and helps stop the plates from sliding under load.
• Improved fatigue resistance: Correct preloading reduces changes in bolt stress under vibration and repeated loading.
• Reduced hole deformation: Limiting movement within the connection helps reduce bearing stress, hole elongation and joint wear.
• High structural performance: Suitable for demanding steel connections requiring strength, stability and controlled movement.

Typical applications: Structural steelwork, bridges, industrial frames, heavy engineering, machinery supports and connections exposed to vibration or changing loads.

Please note: HSFG bolts must be correctly specified by a suitably qualified designer and installed using compatible nuts, hardened washers, correctly prepared contact surfaces and an approved controlled-tightening procedure.