S-91385A123 5-40 x 3/16" ASME B18.3, ASTM F912 Set Screws

Key Features & Benefits at a Glance

• Enhanced vibration resistance with Nylon Patch thread locker, maintaining secure fastening from -50°F to 250°F
• Superior durability and corrosion protection through Black-Oxide Alloy Steel construction and Rockwell C45 hardness
• Precise, reliable thread engagement with Class 3A thread fit for minimal backlash in high-stress applications
• Easy installation and removal using the 1/16" hex drive, ideal for confined spaces with its headless design
• Strong rotational resistance from the cup point tip, which bites into surfaces to prevent slippage
• Broad industrial compatibility with UNC coarse threads and right-hand direction, meeting common assembly requirements
• Regulatory peace of mind by complying with ASME B18.3, RoHS 3, and REACH standards

Professional Applications & Engineering Value

This 5-40 UNC set screw is engineered to address critical challenges in industrial settings, such as component slippage and vibration-induced loosening. The Black-Oxide Alloy Steel material, combined with a Rockwell C45 hardness, ensures long-term wear resistance and protection against rust in harsh environments. Its Nylon Patch thread locker effectively counters vibrations, maintaining clamp load in machinery, automotive, and electronics assemblies exposed to temperature fluctuations from -50°F to 250°F. The headless design and 1/16" hex drive allow for flush mounting in tight spaces, while the cup point provides aggressive gripping on shafts or collars, making it a reliable choice for permanent or semi-permanent fastening solutions.

Specification Summary & Compliance

This set screw adheres to Class 3A thread fit for high precision in Unified National Coarse (UNC) 5-40 thread size, with a length of 3/16". It conforms to ASME B18.3 specifications and is compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) regulations, ensuring environmental safety and material reliability.