S-99291A570 3/8"-16 Locknuts

Key Features & Benefits at a Glance

• Superior vibration resistance through distorted top lock technology that maintains secure fastening under dynamic loads
• Enhanced corrosion protection with zinc-flake coating that provides excellent resistance to industrial environments
• Reliable thread engagement with Class 2B thread fit ensuring consistent performance and easy assembly
• Heavy-duty performance meeting ASTM Grade C specifications for demanding industrial applications
• Industry-standard compatibility with 3/8"-16 UNC coarse threads for broad application across equipment and machinery
• External hex drive design for straightforward installation using standard tools while maintaining structural integrity
• Environmental compliance with REACH and RoHS 3 standards for safe use in regulated industries

Professional Applications & Engineering Value

This zinc-flake-coated steel locknut addresses critical vibration-induced loosening challenges in industrial machinery, automotive assemblies, and heavy equipment. The distorted top lock technology creates consistent interference along the UNC coarse threads, providing reliable locking action without requiring additional locking components. The external hex drive style enables efficient installation in confined spaces while maintaining the structural integrity of the ASTM Grade C material. Engineered for industrial locknut applications where vibration resistance and corrosion protection are paramount, this fastener delivers long-term reliability in demanding environments from manufacturing plants to transportation equipment.

Specification Summary & Compliance

This locknut features Class 2B thread fit with 3/8"-16 UNC coarse threads and right-hand thread direction. Manufactured to ASTM Grade C specifications with standard hex profile measuring 9/16" width and 21/64" height. The product is fully compliant with REACH (EC 1907/2006) and RoHS 3 (2015/863/EU) environmental standards, ensuring safe use across regulated industries.