S-90621A042 3/8"-16 Locknuts

Key Features & Benefits at a Glance

• Superior vibration resistance through the steel insert locking mechanism, preventing loosening in high-stress environments
• Exceptional strength and durability with Grade 8 steel construction, suitable for heavy-duty industrial applications
• Enhanced torque application from the extra wide hex profile, allowing for secure tightening with standard tools
• Reliable thread engagement with UNC 3/8"-16 coarse threads and Class 2B fit, ensuring consistent performance
• Environmental compliance meeting RoHS 3 standards, safe for use in regulated industries
• Optimized for right-hand threading and external hex drive, providing compatibility with common assembly systems
• Robust dimensional stability with 11/16" width and 13/32" height, maintaining integrity under load

Professional Applications & Engineering Value

This Grade 8 steel locknut is engineered to address critical challenges in heavy-duty industrial applications where vibration-induced loosening can compromise safety and performance. The steel insert locking mechanism creates consistent friction against the bolt threads, effectively resisting dynamic loads and thermal cycling common in machinery, automotive, and construction equipment. Its extra wide hex profile distributes clamping force evenly, reducing the risk of stripping during high-torque installation. With UNC coarse threads and Class 2B thread fit, it ensures rapid assembly and reliable seating in demanding environments. The external hex drive compatibility allows for efficient installation using standard wrenches, streamlining maintenance workflows while delivering long-term vibration resistance in critical joints.

Specification Summary & Compliance

This locknut features 3/8"-16 UNC coarse threads with Class 2B thread fit for precise engagement, manufactured to industrial standards for dimensional accuracy. The extra wide hex profile (11/16" width, 13/32" height) and right-hand thread direction ensure compatibility with common assembly requirements. It complies with RoHS 3 (2015/863/EU) regulations, containing no restricted hazardous substances, and meets the mechanical properties specified for Grade 8 strength classification in steel fasteners.