S-91831A145 5/8"-18 Locknuts

Key Features & Benefits at a Glance

• Superior vibration resistance through nylon insert locking that maintains secure fastening under dynamic loads
• Excellent corrosion resistance provided by 18-8 stainless steel construction for extended service life in harsh environments
• Reliable high-temperature performance with nylon insert rated up to 220°F (104°C) for demanding applications
• Precise thread engagement with Class 2B thread fit ensuring smooth installation and consistent clamping force
• Easy installation and removal using standard wrench tools with external hex drive design
• Fine thread configuration (UNF 5/8"-18) offering better tension control and vibration resistance than coarse threads
• Environmental compliance meeting RoHS 3 and REACH standards for global industrial applications

Professional Applications & Engineering Value

This 5/8"-18 UNF nylon insert locknut delivers critical vibration resistance in demanding industrial environments where secure fastening is paramount. The 18-8 stainless steel construction provides exceptional corrosion resistance, making it ideal for applications exposed to moisture, chemicals, or outdoor conditions. The nylon insert locking mechanism creates consistent friction against the mating bolt, preventing loosening from vibration or thermal cycling while allowing for multiple reuses. With its Class 2B thread fit and UNF fine thread profile, this locknut ensures precise engagement and superior tension control in machinery, automotive assemblies, and industrial equipment where reliability cannot be compromised. The external hex drive facilitates quick installation with standard tools, reducing assembly time while maintaining the integrity of critical connections.

Specification Summary & Compliance

This locknut features precise Class 2B thread fit according to UNF standards with 5/8"-18 fine thread specification. The external hex design measures 15/16" across flats with a 3/4" height profile. Manufacturing complies with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) environmental regulations, ensuring safe use across global industrial markets. The nylon insert maintains locking performance up to the maximum temperature rating of 220°F while the 18-8 stainless steel construction provides durable, corrosion-resistant performance in demanding applications.