S-99291A720 9/16"-18 Locknuts

Key Features & Benefits at a Glance

• Superior vibration resistance through top lock distorted thread design that maintains clamp force in high-stress environments
• Exceptional corrosion protection with zinc-flake coating that provides long-lasting performance in harsh industrial conditions
• High-strength performance meeting ASTM Grade C specifications for demanding applications requiring reliable fastening
• Precise thread engagement with Class 2B fine thread fit ensuring smooth assembly and consistent locking performance
• Easy installation and removal using standard 7/8" external hex drive compatible with common wrench tools
• Environmental compliance assurance with REACH and RoHS 3 certification for global industrial applications
• Optimized fine thread design (18 TPI) providing better tension control and improved resistance to loosening

Professional Applications & Engineering Value

This 9/16"-18 UNF steel locknut with distorted thread technology addresses critical vibration-induced loosening challenges in industrial machinery, automotive assemblies, and heavy equipment. The top lock distorted thread creates controlled interference that maintains preload under dynamic loads, while the zinc-flake coating provides superior corrosion resistance compared to conventional plating methods. Engineered with fine thread spacing and Class 2B thread fit, this locknut delivers precise engagement and consistent performance in applications where vibration resistance and reliability are paramount. The external hex drive design ensures compatibility with standard tools, streamlining maintenance and assembly processes in industrial settings.

Specification Summary & Compliance

This high-performance locknut features 9/16"-18 UNF fine threads with Class 2B thread fit for precision engagement. The distorted thread locking mechanism operates on the top section for reliable vibration resistance. Manufacturing complies with ASTM Grade C strength requirements, ensuring consistent mechanical performance. Environmental compliance includes REACH (EC 1907/2006) and RoHS 3 (2015/863/EU) certifications, making this component suitable for regulated industrial applications worldwide. Dimensional specifications include 7/8" width across flats and 31/64" height for standardized installation.