The Lawson Products Tuff-Torq Fastening Systems are suitable for replacing production Grade 8 and Grade 5 fasteners with a strong, reliable fastener. The Grade 8 maintenance engineered fastening system with matched strength components features a higher hex head for better wrenching during installation and removal, vibration-resistant maintenance engineered UNJ thread design, maximum clamping load without dishing or warping, consistent clamp loads with wax-coated hex nuts and easy assembly with chamfered ends.