Bolt Kit - 6pt. (5) 3/8-16 x 2.250

The Bolt Kit - 6pt. (5) 3/8-16 x 2.250 from ARP is a precision fastener assembly purpose-built for critical structural and performance applications in tactical, automotive, and industrial environments. This five-piece bolt kit delivers the reliability that law enforcement and military operators demand when assembling high-stress mechanical systems where fastener failure is not an option. Whether you're building a custom AR platform, securing critical chassis components, or assembling engine internals, the 3/8-16 thread specification and 2.250-inch length provide the exact clamping geometry needed for load-critical joints.

ARP's 6-point bolt head design—versus the weaker 12-point alternative—maximizes contact surface area with your socket or wrench, reducing the risk of rounding and fastener slip during installation. The 3/8-inch diameter with 16 threads-per-inch (TPI) specification delivers superior tensile strength and consistent preload across repeated use cycles, critical for applications experiencing vibration or thermal cycling. ARP's manufacturing process ensures tight tolerances and uniform hardness throughout, preventing the premature fatigue and shear failures common with inferior fasteners. Each bolt in this five-piece set is individually engineered to specification, making this kit ideal for single-platform builds or replacement of worn fasteners in existing assemblies.

Operators and gunsmiths standardize on ARP fasteners for AR-15/AR-10 upper receiver assemblies, bolt carrier group installations, and buffer tube attachment systems where micro-movement can degrade accuracy and reliability. The 2.250-inch length accommodates most receiver extension threads and critical bolt-pattern spacing in mil-spec and commercial platforms. At 0.44 lbs for the complete five-piece set, weight penalty is negligible while reliability gains are measurable. Installation requires standard SAE or metric socket tooling and should follow manufacturer torque specifications for your specific application to achieve optimal preload and prevent joint separation under operational stress.