Self-Locking 12pt. Nut 3/8-24 (1)

The ARP Self-Locking 12pt. Nut 3/8-24 (1) is a precision fastening component engineered for high-reliability applications where vibration-induced loosening must be eliminated. Designed for use in motorsports, aerospace, and industrial assembly, this self-locking nut prevents fastener failure without requiring secondary locking devices such as lock washers or thread-locking compounds. Its mechanical locking action makes it ideal for technicians and engineers who demand dependable, maintenance-free fastening in critical assemblies.

Manufactured from cadmium-plated steel, this self-locking nut features a robust 12-point head geometry that provides superior grip engagement and reduces the risk of rounding during installation and removal. The 3/8-24 thread specification delivers precise fitment on corresponding bolts and studs, while the cadmium plating provides corrosion resistance and consistent surface lubricity across repeated tightening cycles. The mechanical self-locking mechanism—typically a deformed thread or nylon insert—creates interference during assembly, generating the clamping force necessary to resist loosening under vibration, thermal cycling, and dynamic loads without degrading the fastener's structural integrity.

This fastener benefits engine builders, transmission specialists, and structural assembly operations where bolt preload retention is non-negotiable. Common applications include cylinder head fastening, intake manifold assembly, and suspension component securing in both street and competition environments. The single-unit quantity allows for targeted replacement or small-batch repairs, while the compact 1.4 x 0.8 x 2.85 in. dimensions ensure compatibility with standard 3/8-24 threaded holes and tight engine bay spacing. Installation requires no special tools beyond standard wrenches and torque equipment, making it a practical upgrade over conventional nuts in any assembly requiring maximum vibration resistance.