S-90715A187 5/8"-18 Locknuts

Key Features & Benefits at a Glance

• Superior vibration resistance thanks to the nylon insert that securely locks the nut in place, preventing loosening under dynamic loads
• Excellent corrosion resistance in harsh environments due to 316 stainless steel construction, ideal for marine and chemical applications
• High-temperature durability with a nylon insert rated up to 220°F, ensuring reliable performance in demanding thermal conditions
• Precise thread engagement with Class 2B fit for smooth assembly and consistent clamping force in fine-threaded applications
• Easy installation and removal using standard external hex drive tools, reducing labor time and improving maintenance efficiency
• Long-term reliability with a standard hex profile and robust design that withstands repeated use without degradation
• Compliance with environmental regulations including RoHS 3 and REACH, ensuring safe use in regulated industrial sectors

Professional Applications & Engineering Value

This 5/8"-18 UNF nylon insert locknut is engineered to address critical challenges in industrial settings where vibration, corrosion, and temperature fluctuations compromise fastener integrity. The 316 stainless steel material provides exceptional resistance to corrosive agents like saltwater and chemicals, making it ideal for marine equipment, chemical processing plants, and offshore structures. The nylon insert offers reliable locking action, maintaining clamp load under severe vibrations in machinery, automotive assemblies, and heavy equipment. With a fine UNF thread and Class 2B thread fit, it ensures precise alignment and secure fastening in high-stress applications, reducing the risk of thread stripping and assembly failures. This locknut delivers consistent performance, minimizing downtime and maintenance costs in demanding engineering environments.

Specification Summary & Compliance

This locknut features a 5/8"-18 UNF fine thread with Class 2B thread fit for accurate dimensional tolerance, adhering to standardized thread specifications. The external hex drive design (15/16" width and 3/4" height) ensures compatibility with common tools. It complies with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) regulations, confirming the absence of hazardous substances and supporting use in environmentally conscious industrial applications.