Shear Strength of High-Strength Bolts

Double shear tests of single 7/8-in. and 1-in. high-strength bolts are reported. Altogether, ninety-six A325 bolts were tested in A7 steel jigs or in A440 steel jigs. Eighty-four A354BC, A354BD, and A490 bolts were tested in jigs made of A440 or constructional alloy steel. The effect of a number of variables on the shear strength and deformation at ultimate load was studied. The study showed that bolts tested in tension jigs had shear strengths 10% lower than bolts tested in compression jigs. Initial preload, faying surface condition, and type of connected material had no significant influence on shear strength. The shear resistance of a bolt was directly reflected by the available shear area. Also, it was found that the ultimate shear stress was approximately 73% of the tensile strength for A325 bolts tested in compression jigs and approximately 68% when these bolts were tested in tension jigs. For A354BC, A354BD, and A490 bolts, the corresponding values were 69% and 62%.