S-91831A120 1/4"-28 Locknuts

Key Features & Benefits at a Glance

• Superior vibration resistance through nylon insert locking technology that maintains secure fastening in high-motion environments
• Excellent corrosion resistance provided by 18-8 stainless steel construction for extended service life in demanding conditions
• Reliable performance at elevated temperatures with nylon insert rated for continuous operation up to 220°F
• Precise thread engagement with Class 2B thread fit ensuring consistent torque values and reduced cross-threading risk
• Easy installation and removal with standard external hex drive design compatible with common wrench tools
• Fine thread configuration (UNF 1/4"-28) delivering enhanced clamping force and superior resistance to loosening
• Regulatory compliance assurance meeting RoHS 3 and REACH standards for global industrial applications

Professional Applications & Engineering Value

This 1/4"-28 UNF nylon insert locknut delivers critical vibration resistance in demanding industrial environments where constant motion threatens fastener integrity. The 18-8 stainless steel construction provides essential corrosion resistance for applications exposed to moisture, chemicals, or outdoor elements, while the nylon insert locking mechanism creates consistent friction that prevents spontaneous loosening without damaging mating threads. Engineered with Class 2B thread fit and UNF fine threading, this external hex locknut ensures precise installation in machinery, automotive assemblies, and electronic enclosures where reliability is paramount. The 220°F temperature rating makes it suitable for engine compartments, industrial equipment, and other thermally challenging applications where traditional locking methods may fail.

Specification Summary & Compliance

This locknut features 1/4"-28 UNF fine threads with Class 2B thread fit per UNF standards, ensuring precise dimensional accuracy and reliable performance. The external hex design measures 7/16" across flats with 5/16" height for standard tool compatibility. Manufactured from 18-8 stainless steel with right-hand threading and nylon insert locking, this component is fully compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) regulations, meeting the latest environmental and safety standards for industrial fasteners.