1/2-20 12pt. Nut (2pk)

The ARP 1/2-20 12-point nut (2-pack) is a precision fastener engineered for high-performance engine assembly and critical mechanical applications. Manufactured from chromoly steel with black oxide finish, this fastener delivers the strength and corrosion resistance demanded in motorsports, engine rebuilds, and heavy-duty industrial fastening where standard hardware falls short.

The 1/2-20 thread specification indicates a half-inch diameter with 20 threads per inch, providing fine-pitch engagement critical for precision torque application and vibration resistance. The 12-point head design allows multiple approach angles during installation and removal, reducing the risk of rounding in confined engine compartments. Chromoly construction offers superior tensile strength compared to standard steel, essential for fastening components subject to thermal cycling, high clamping loads, or engine vibration. The black oxide coating provides base-level corrosion protection suitable for internal engine use and protected environments.

This two-pack format serves engine builders, machine shops, and motorsports enthusiasts who require matching fastener sets for cylinder head bolts, intake manifold mounting, turbocharger installations, or other critical engine fastening points. ARP hardware is widely specified in performance engine assembly where fastener reliability directly impacts engine integrity and longevity. The chromoly and black oxide combination is standard across ARP's professional-grade fastener lineup.

Users should verify torque specifications for their specific application and use appropriate torque wrench technique to ensure proper clamping force. Chromoly fasteners are sensitive to over-torque, which can reduce preload consistency and component lifespan.