S-99291A730 5/8"-18 Locknuts

Key Features & Benefits at a Glance

• Reliable Vibration Resistance: Distorted top lock thread design ensures secure, long-lasting fastening under high-vibration conditions, reducing maintenance needs.
• Superior Corrosion Protection: Zinc-flake coating provides excellent resistance to rust and environmental degradation, extending service life in harsh industrial settings.
• High-Strength Performance: ASTM Grade C classification guarantees heavy-duty mechanical strength, suitable for demanding applications without failure.
• Precise Thread Fit: Class 2B fine UNF threads offer smooth engagement and consistent clamping force, minimizing the risk of cross-threading.
• Easy Installation and Removal: External hex drive allows for straightforward tool access, speeding up assembly and disassembly processes.
• Compliance with Safety Standards: Meets REACH and RoHS 3 regulations, ensuring environmental safety and suitability for global industrial markets.
• Optimized Dimensions: Standard 15/16" width and 35/64" height provide a balanced profile for space-constrained assemblies while maintaining structural integrity.

Professional Applications & Engineering Value

This 5/8"-18 UNF locknut is engineered to address common industrial challenges such as loosening from vibrations and corrosion in demanding environments. The distorted thread locking mechanism at the top ensures a tight, reliable grip that resists back-off, making it ideal for machinery, automotive, and construction applications where safety is critical. Made from zinc-flake-coated steel, it offers enhanced durability against moisture and chemicals, reducing downtime and replacement costs. The external hex drive facilitates quick installation with standard tools, while the fine UNF thread and Class 2B fit provide precise alignment and consistent performance in heavy-duty assemblies. By integrating these features, this locknut delivers long-term reliability and efficiency in industrial fastening systems.

Specification Summary & Compliance

This locknut adheres to precise dimensional standards, including a Class 2B thread fit for accurate engagement and UNF fine thread specifications (5/8"-18). It complies with ASTM Grade C for mechanical strength and is manufactured to meet REACH (EC 1907/2006) and RoHS 3 (2015/863/EU) regulations, ensuring environmental and safety compliance. The product features a standard hex profile with dimensions of 15/16" width and 35/64" height, supporting reliable performance in various industrial applications.