S-91385A535 1/4"-20 x 3/8" ASME B18.3, ASTM F912 Set Screws

Key Features & Benefits at a Glance

• Enhanced vibration resistance with nylon patch thread locker, preventing loosening in dynamic applications from -50°F to 250°F.
• Superior corrosion protection from black-oxide coating on alloy steel, extending service life in harsh industrial environments.
• High-strength durability with Rockwell C45 hardness, ensuring reliable performance under heavy loads and repeated use.
• Precise thread engagement with UNC Class 3A fit, providing secure fastening and reduced risk of cross-threading.
• Easy installation and removal using a 1/8" hex drive, allowing for efficient maintenance in confined spaces.
• Secure component positioning with cup tip design, minimizing surface damage and improving grip on shafts or collars.
• Compliance with industry standards including ASME B18.3, RoHS 3, and REACH, ensuring safety and environmental responsibility.

Professional Applications & Engineering Value

This black-oxide alloy steel set screw is engineered to address common industrial challenges such as component slippage and vibration-induced failure. The nylon patch thread locker maintains locking integrity across a wide temperature range (-50°F to 250°F), making it ideal for machinery, automotive assemblies, and electrical enclosures where thermal cycling occurs. Its UNC coarse thread and Class 3A fit enable quick, accurate installation with high resistance to stripping, while the headless hex drive design saves space and allows flush mounting in precision equipment. By combining robust materials with advanced locking technology, this screw delivers reliable fastening solutions that reduce maintenance downtime and enhance operational safety in demanding B2B environments.

Specification Summary & Compliance

This set screw adheres to UNC thread standards with a Class 3A thread fit for precise dimensional accuracy and coarse thread spacing. It meets ASME B18.3 specifications (referencing ASTM F912) and is compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) regulations, ensuring environmental safety and material reliability. The manufacturing process focuses on consistent performance, with a cup tip and right-hand thread direction for standardized industrial use.