Until the introduction of Amendment AMD l787 in July 1975, BS 449 gave the steelwork designer no guidance concerning the ultimate or design load of a black bolt, when it is subjected to the combined effect of tension and shear forces. It was therefore unavoidable that different designers had their own 'design methods' for the purpose of checking such bolts. The work described in this paper was carried out with a view to providing the designer with information regarding the behaviour, response, and ultimate carrying capacity of black bolts subjected to varying tension-shear ratios.
H. Shakir-Khalil and C.M. Ho