S-91853A515 1/4"-28 Locknuts

Key Features & Benefits at a Glance

• Superior Locking Security: Cotter pin design ensures permanent fastening, preventing loosening under extreme vibration and dynamic loads in industrial applications.
• Excellent Corrosion Resistance: Made from 18-8 Stainless Steel, this locknut provides long-term durability and reliability in harsh or outdoor environments.
• Precision Thread Fit: Class 2B thread fit offers consistent, reliable engagement with mating threads, reducing the risk of cross-threading and ensuring a secure assembly.
• Fine Thread Advantage: UNF fine threads allow for finer adjustment and greater tension control in precision assemblies compared to coarse threads.
• Standard Hex Drive: External hex design enables easy installation and removal with common wrenches, streamlining maintenance and assembly processes.
• Environmental Compliance: REACH and RoHS 3 compliance ensures the nut meets stringent international regulations for hazardous substances, supporting responsible manufacturing.
• Optimized Slot Dimensions: Precisely sized slot (min. depth 0.09", min. width 0.07") accommodates a standard 1/16" cotter pin for quick and secure locking.

Professional Applications & Engineering Value

This 1/4"-28 UNF stainless steel cotter pin locknut is engineered for high-stakes applications where vibration-induced loosening can lead to equipment failure or safety hazards. The 18-8 stainless steel construction provides exceptional resistance to corrosion and oxidation, making it ideal for marine, automotive, and heavy machinery environments. The UNF fine thread and Class 2B thread fit ensure precise, repeatable fastening in assemblies requiring accurate tension and alignment, such as in aerospace components or precision industrial machinery. The cotter pin locking mechanism offers a reliable, mechanical lock that is superior to nylon inserts in high-temperature scenarios, ensuring long-term joint integrity without compromising on REACH and RoHS compliance for global supply chain compatibility.

Specification Summary & Compliance

This locknut adheres to UNF fine thread standards with a Class 2B thread fit for consistent dimensional accuracy. Key specifications include a thread size of 1/4"-28, right-hand thread direction, standard hex profile (7/16" width), and a height of 9/32". It is manufactured from 18-8 stainless steel and is fully compliant with REACH (EC 1907/2006) and RoHS 3 (2015/863/EU) directives, ensuring it meets rigorous environmental and safety standards for industrial use.