Bolt Kit - 6pt. (5) 5/16-18 x 4.000

The Bolt Kit - 6pt. (5) 5/16-18 x 4.000 by ARP is engineered for builders and mechanics who demand critical fastening reliability in high-stress engine and drivetrain applications. These premium fasteners are essential when assembling cylinder heads, intake manifolds, or structural components where vibration resistance and consistent clamping force are non-negotiable. Whether you're rebuilding a classic V8, upgrading a performance engine, or restoring a vintage truck, this five-piece kit delivers the precision fastening solution professional technicians and serious enthusiasts rely on.

ARP bolts are manufactured from premium-grade alloy steel with a proprietary heat-treatment process that ensures superior tensile strength and consistent preload retention under thermal cycling and vibration. The 5/16-18 thread pitch provides optimal engagement in standard automotive ports and fastening points, while the 4.000-inch length accommodates both shallow and mid-depth applications common in engine block and cylinder head assemblies. The 6-point socket head design maximizes contact area and dramatically reduces the risk of bolt rounding during installation—a critical advantage when working with softer aluminum or cast-iron components where stripping is a real concern.

This bolt kit is ideal for engine rebuilds, head gasket replacement, and custom engine modifications where OEM hardware may not meet performance demands. Technicians and builders benefit from ARP's track record in drag racing, marine, and high-horsepower applications—the same fastening science that holds together 1,000+ hp engines works equally well for street builds and restoration projects. Always use a torque wrench with ARP's published specifications for your specific application, and apply a thin coat of ARP Ultra-Torque lubricant to ensure accurate preload and repeatable results across multiple fastening cycles.