Hex Head Bolt 5/8-18 x 2-1/2 Grade 5

The Hex Head Bolt 5/8-18 x 2-1/2 Grade 5 from ALLSTAR PERFORMANCE is a critical fastener for high-performance engine builds, suspension assemblies, and structural vehicle modifications where load-bearing reliability is non-negotiable. Whether you're assembling a stroker motor, reinforcing a frame connector, or securing transmission mounts, this bolt delivers the tensile strength and shear resistance that serious fabricators and engine builders demand. Grade 5 fasteners represent the sweet spot for automotive work—offering superior holding power compared to standard hardware without the brittleness or cost of exotic alloys.

Grade 5 bolts achieve a minimum tensile strength of 120,000 PSI, making them ideal for applications involving vibration, thermal cycling, and dynamic loads typical of engine compartments and suspension systems. The 5/8-inch diameter with an 18 threads-per-inch (TPI) pitch provides a fine thread profile that resists vibration-induced loosening better than coarse-pitch alternatives, while the 2-1/2 inch length accommodates deep-hole applications in engine blocks, cylinder head studs, and frame bracketing. The hex head design allows secure grip with standard and deep-well sockets, reducing the risk of bolt rounding during assembly or service.

This fastener excels in engine bay environments, turbo mounting, water pump installations, and any structural modification where consistent clamping force is essential. Professional mechanics and fabricators rely on ALLSTAR PERFORMANCE Grade 5 hardware for critical assemblies because oversized or undersized fasteners compromise reliability and void warranties. Always verify thread pitch and bolt length against your specific application, use proper torque specifications (typically 80–95 ft-lbs for 5/8-18 Grade 5 in steel), and apply threadlocker on high-vibration builds to ensure long-term security and safety.