S-99291A280 5/8"-18 Locknuts

Key Features & Benefits at a Glance

• Superior vibration resistance with distorted top lock thread design that maintains secure fastening under dynamic loads.
• Enhanced corrosion protection through zinc yellow-chromate plating, extending service life in harsh industrial environments.
• High-strength performance certified to ASTM Grade C, ensuring reliable clamping force for heavy-duty applications.
• Precise thread engagement with Class 2B fit and UNF fine threads, reducing the risk of cross-threading and improving assembly accuracy.
• Easy installation and removal using standard external hex drive, compatible with common wrenches for efficient maintenance.
• Durable material construction from plated steel, offering excellent wear resistance and long-term reliability.
• Wide compatibility with 5/8"-18 UNF fine thread bolts, ideal for machinery, automotive, and structural assemblies.

Professional Applications & Engineering Value

This 5/8"-18 UNF locknut is engineered to address critical challenges in high-vibration and heavy-load environments, such as industrial machinery, automotive systems, and construction equipment. The distorted thread locking type creates consistent interference fit, preventing loosening from dynamic stresses without requiring additional locking devices. Made from zinc yellow-chromate-plated steel, it resists corrosion from moisture, chemicals, and outdoor exposure, reducing maintenance frequency and downtime. The fine thread spacing and Class 2B thread fit ensure precise alignment and secure fastening, minimizing the risk of assembly errors. With ASTM Grade C certification, it delivers reliable strength for demanding applications, enhancing overall system integrity and safety in B2B procurement scenarios where performance and compliance are paramount.

Specification Summary & Compliance

This locknut adheres to UNF thread standards with a Class 2B thread fit for consistent dimensional accuracy. It meets ASTM Grade C strength requirements and is manufactured with a distorted top lock thread type and right-hand thread direction. The product complies with industry specifications for heavy-duty fasteners and is suitable for applications requiring fine thread engagement. Materials and processes align with common industrial standards for durability and performance.