Self-Locking Hex Nut 5/16-24 (1)

The Self-Locking Hex Nut 5/16-24 from ARP is a precision fastener engineered for critical applications where vibration-induced loosening poses a reliability risk. Whether you're assembling high-performance engine components, suspension systems, or structural joints that experience constant movement, this self-locking nut prevents fastener migration without requiring additional locking compounds or safety wire. Trusted by motorsport professionals, automotive builders, and industrial maintenance teams, this mechanical locking solution delivers consistent performance across temperature cycling and demanding operational environments.

This self-locking hex nut features a nylon insert or mechanical deformation design that creates friction against the bolt threads, resisting rotational movement while maintaining full clamp load integrity. The 5/16-24 thread specification matches standard fastener sizing for precision machinery and race-engine applications where metric and SAE standards intersect. ARP's cadmium-plated steel construction provides superior corrosion resistance and a consistent friction coefficient, ensuring predictable locking performance across hundreds of assembly cycles. The mechanical locking mechanism functions across a wide temperature range, making it suitable for both cryogenic environments and high-heat engine bays without degradation of the locking feature.

Buyers assembling custom engine builds, competition vehicles, or precision machinery will recognize the value of ARP's self-locking design—eliminating the need for lock washers, thread-locking adhesives, or secondary safety measures. This single-piece nut simplifies assembly procedures and reduces material costs on high-volume builds. Installation is straightforward: torque to specification using standard hex-head wrenches, and the integrated locking mechanism engages immediately. Verify compatibility with your bolt's 5/16-24 thread pitch before purchase, and note that repeated disassembly may require replacement of the nut to maintain locking effectiveness on critical joints.