S-99291A680 3/8"-24 Locknuts

Key Features & Benefits at a Glance

• Superior vibration resistance through top lock distorted thread design that maintains clamp force in high-stress applications
• Enhanced corrosion protection with zinc-flake coating that provides superior resistance to harsh industrial environments
• Reliable mechanical performance meeting ASTM Grade C specifications for consistent strength and durability
• Precision thread engagement with Class 2B fine thread fit ensuring secure fastening and reduced loosening risks
• Industry-standard compatibility with 3/8"-24 UNF fine thread patterns for seamless integration into existing assemblies
• Easy installation and removal using standard wrench tools thanks to the external hex drive design
• Environmental compliance assurance with RoHS 3 and REACH regulations for global manufacturing applications

Professional Applications & Engineering Value

This high-performance locknut addresses critical vibration-induced loosening challenges in industrial machinery, automotive assemblies, and heavy equipment applications. The distorted thread locking mechanism creates consistent interference along the mating threads, providing reliable vibration resistance without requiring additional locking components. Manufactured from zinc-flake-coated steel, this fastener delivers exceptional corrosion resistance in demanding environments where moisture, chemicals, or temperature variations would compromise standard fasteners. The 3/8"-24 UNF fine thread configuration ensures precise engagement with mating components, while the external hex drive facilitates efficient installation in confined spaces. Engineered to ASTM Grade C standards, this locknut maintains clamping force integrity under dynamic loading conditions, making it ideal for critical assemblies where failure is not an option.

Specification Summary & Compliance

This precision locknut features Class 2B thread fit tolerances with 3/8"-24 UNF fine threads in right-hand orientation. The top lock distorted thread design conforms to industrial locking standards, while the zinc-flake coating provides superior surface protection. Manufacturing compliance includes ASTM Grade C mechanical properties, RoHS 3 (2015/863/EU) environmental standards, and REACH (EC 1907/2006) substance restrictions. Physical dimensions include 9/16" width across flats and 21/64" height for standardized wrench compatibility and space-efficient designs.