Hex Nut Kit w/Flange 5/16-18 (10pk)

The ARP Hex Nut Kit w/Flange 5/16-18 (10pk) delivers premium fastening solutions for high-performance engine builds, race applications, and critical machinery assembly. This 10-piece set is engineered for users who demand reliability in demanding conditions—from serious engine builders and automotive technicians to industrial maintenance professionals. ARP's chromoly construction combined with black oxide finish addresses the need for corrosion resistance and fatigue strength where standard fasteners fall short.

These 5/16-18 thread hex nuts feature a 12-point head geometry that allows superior tool access and reduced fastener rounding compared to 6-point designs. The flanged design distributes clamping load over a larger surface area, which reduces joint stress and vibration loosening—critical in engine compartments and suspension systems subject to continuous thermal cycling and mechanical shock. Chromoly construction delivers exceptional tensile strength and fatigue resistance, while the black oxide coating provides a thin, hard protective layer that resists corrosion without adding significant thickness. Each nut is precision-manufactured to ARP's exacting standards, ensuring consistent thread engagement and reliable clamping force retention.

This kit is ideal for engine rebuilds, intake manifold installations, cylinder head assembly, and any critical fastening application where vibration and stress require superior holding power. The 10-pack format provides coverage for multiple assemblies or replacement of existing fasteners across a single project. Installation requires standard wrenches or sockets compatible with 5/16-inch hex sizes; users should verify thread compatibility with existing studs or bolts before assembly. These fasteners are widely trusted by engine builders, race teams, and OEM service centers seeking ARP's proven reputation for quality and reliability.