S-99291A130 3/8"-16 Locknuts

Key Features & Benefits at a Glance

• Superior vibration resistance through distorted thread top lock technology, preventing loosening in high-stress environments
• Enhanced corrosion protection with zinc yellow-chromate plating, extending service life in harsh industrial conditions
• Heavy-duty performance certified to ASTM Grade C standards, ensuring reliable performance under extreme loads
• Easy installation and removal with standard external hex drive design, compatible with common wrench tools
• Precise thread engagement with Class 2B fit and UNC coarse threads, providing secure fastening without cross-threading
• Reusable locking capability maintains consistent locking performance through multiple installation cycles
• Optimal dimensional stability with 9/16" width and 21/64" height profile for standard application requirements

Professional Applications & Engineering Value

This 3/8"-16 UNC top lock locknut delivers exceptional engineering value through its distorted thread locking mechanism that actively counters vibrational loosening - a critical concern in industrial machinery, automotive assemblies, and construction equipment. The zinc yellow-chromate-plated steel construction provides dual-layer corrosion resistance, making it ideal for applications exposed to moisture, chemicals, or outdoor elements. The external hex drive style ensures straightforward installation with standard tools while maintaining a low profile. Engineered to ASTM Grade C specifications, this heavy-duty locknut maintains clamping force integrity in dynamic loading scenarios, preventing catastrophic failures in critical fastening joints. The combination of coarse UNC threading and Class 2B fit guarantees reliable engagement while accommodating minor misalignments in assembly processes.

Specification Summary & Compliance

This locknut features precision 3/8"-16 UNC coarse threads with Class 2B thread fit for optimal engagement and right-hand thread direction. Manufacturing complies with ASTM Grade C strength requirements, ensuring consistent mechanical properties. The zinc yellow-chromate plating provides corrosion protection while maintaining dimensional accuracy with 9/16" width and 21/64" height specifications. The top lock distorted thread design follows industry-standard locking principles for vibration-resistant applications. Materials and processes conform to relevant industrial standards for heavy-duty fastening solutions.