Comparing torsional shear bolt designs for heavy loads
Heavy-load steel connections depend on more than simply selecting the strongest available bolt. The performance of a connection is also affected by bolt diameter, material grade, grip length, thread position, surface condition, installation method and the compatibility of the complete bolt assembly. Torsional shear bolts , also known as tension control bolts or twist-off bolts, are widely used in bridges, high-rise buildings, industrial plants, railway structures and other large steel projects. Their distinctive spline-end design allows the outer socket to tighten the nut while the inner socket holds the spline. Once the specified pretension is reached, the spline shears off, providing a visible indication that installation has been completed. However, not every torsional shear bolt design performs equally under heavy loads. Engineers and procurement teams must compare the complete fastening system rather than choosing a product based only on diameter or tensile strength. ...