1. Bolts, large bihexagonal head, close tolerance normal shank, medium length thread, in heat resisting nickel base alloy, passivated. Classification: 1550 MPa (at ambient temperature) /315°C. (15th December 1996) Authors: British Standards Institution, Record Type: Book Extent: 1 online resource (12 pages) View Content: Available online (eLD content is only available in our Reading Rooms) ↗