Hex Nut - 3/8-24 (1)

The ARP Hex Nut 3/8-24 (1) is a precision-engineered chromoly fastener designed for high-strength applications where standard hardware falls short. Manufactured from chromoly steel and finished in black oxide for corrosion resistance, this 9/16-inch hex head nut delivers the reliability demanded in motorsports, engine assembly, and precision machinery work where vibration and extreme loads are constants.

The 3/8-24 thread specification indicates a 3/8-inch diameter with 24 threads per inch, a standard fine-pitch configuration that provides superior clamping force consistency compared to coarse-pitch alternatives. Chromoly construction—an iron-chromium-molybdenum alloy—offers tensile strength significantly higher than mild steel, making it the standard choice for engine builders, transmission specialists, and performance assemblers. The black oxide coating provides a thin, protective layer that resists surface corrosion while maintaining dimensional accuracy critical for precision fits. The 9/16-inch hex head accommodates standard wrenches and sockets, ensuring compatibility with common hand tools and impact equipment used in automotive and mechanical assembly environments.

This fastener serves builders, mechanics, and technicians working with high-performance engines, custom automotive builds, and machinery requiring fail-safe fastening under stress. Whether securing critical engine components, transmission housings, or custom fabrication assemblies, ARP fasteners are recognized across motorsports and industrial sectors as the standard for applications where bolt failure is not an option. Individual nut sales allow for replacement or supplementary hardware procurement without bulk purchasing, ideal for restocking or completing custom assembly projects.

When selecting fasteners for high-load applications, material composition and thread pitch directly impact joint integrity and longevity. Chromoly fasteners paired with fine-pitch threads deliver superior preload consistency and resistance to vibration loosening—critical factors in engine compartments, transmission cases, and performance machinery where temperature cycling and mechanical stress are routine.