Following on from previous work with carbon steel bolts, SCI has just completed a test programme for the stainless steel equivalent. Bolts were tested in shear and in tension and design resistances determined following the procedures described in BS EN 1990-1 Annex D. As expected, the bolts ultimately fail in tension at the smallest cross section. The failure loads in both tension and shear were remarkably consistent, demonstrating accurate machining of the assembly and uniform material properties. In bearing, the behaviour of the supporting material is important, not the bolt, so there is no difference between the performance of carbon steel and stainless steel bolts. In common with any ‘blind’ fixing, the resistance of the supporting element must be verified, as the tension resistance reported is that of the bolt assembly alone. In the common application of connections to hollow sections, the strength or deformation of the relatively thin wall of the hollow section will be the weak link in the joint, not the bolt assembly.
The SCI report and design resistances are available from the Blind Bolt website, http://www.blindbolt.co.uk.