It is known that the use of high strength friction grip bolts for structural steelwork provides a method of jointing which is comparable or superior to that of hot driven rivets. There are, of course, complications associated with the use of these bolts in such matters as tools; the effect of bolt thread conditions (whether dry, oiled, plated, greased etc.,) on the tension/torque relationship, and the coefficient of friction between mating surfaces. Investigations towards improving the technique in relation to these and other factors should clearly embrace not only alternative but also supplementary methods of improving joint efficiency.
J. Ritchie, P. Gregory and A. J. Bangay