S-91831A124 12-28 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 with 18-8 stainless steel construction for long-term durability in harsh industrial conditions
• Reliable high-temperature performance with nylon insert rated up to 220°F for thermal stability in demanding applications
• Precise thread engagement with Class 2B UNF fine threads ensuring consistent, accurate fit and reduced cross-threading risk
• Easy installation and removal using standard external hex drive compatible with common wrenching tools
• Environmental compliance assurance meeting RoHS 3 and REACH standards for safe use in regulated industries
• Optimized dimensional design with 7/16" width and 5/16" height providing balanced strength-to-size ratio

Professional Applications & Engineering Value

This 12-28 UNF nylon insert locknut delivers critical vibration-resistant performance for industrial machinery, automotive assemblies, and electrical equipment where constant motion threatens fastener integrity. The 18-8 stainless steel construction provides exceptional corrosion resistance in humid or chemically aggressive environments, while the nylon insert locking mechanism creates consistent friction that prevents loosening without damaging mating threads. Engineered with Class 2B UNF fine threads, this external hex locknut ensures precise fitment in applications requiring accurate torque values and reliable clamping force maintenance. The 220°F temperature rating makes it suitable for engine compartments, industrial ovens, and other thermal cycling scenarios where plastic components might typically fail.

Specification Summary & Compliance

This locknut features 12-28 UNF fine threads with Class 2B thread fit per UNF standards, ensuring precise dimensional accuracy and consistent performance. The external hex drive measures 7/16" across flats with 5/16" height profile. Manufacturing complies with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) regulations, confirming environmental safety and restricted substance compliance for global industrial applications. The nylon insert locking system maintains effectiveness within the specified -220°F temperature range while providing reusable locking capability.