Six-bolt hub cap hardware kit with Grade 5 cap screws and Stanlok lock washers for commercial truck hubs Steel construction throughout for strength and durability in threaded hub cap mounting applications Bolt size at 0.31" - 18 x 1.00" cap screws (6 pieces) for secure engagement in 6-bolt hub cap patterns Stanlok lock washer type at 0.31" (6 pieces) for vibration-resistant fastener retention on the hub face Total of 12 components in one kit with 6 cap screws and 6 lock washers for a complete 6-bolt installation Threaded mounting type for a tool-driven, torque-controlled hub cap fastening solution on commercial axles