S-91375A105 4-40 x 3/16" ASME B18.3, ASTM F912 Set Screws

Key Features & Benefits at a Glance

• Superior corrosion resistance with Black-Oxide finish, extending service life in harsh industrial environments.
• Exceptional thread precision with Class 3A fit for reliable, vibration-resistant fastening in critical assemblies.
• High-strength durability from Alloy Steel and Rockwell C45 hardness, resisting wear and deformation under load.
• Secure, flush mounting with headless hex drive and cup tip design, preventing loosening and component damage.
• Wide compatibility with UNC coarse threads and 4-40 size, ensuring easy integration into standard industrial equipment.
• Confident compliance meeting ASME B18.3, RoHS 3, and REACH standards for safe, regulated use globally.
• Efficient installation using a 0.050" hex drive, allowing quick, tool-accessible tightening in confined spaces.

Professional Applications & Engineering Value

This 4-40 UNC set screw is engineered to address common industrial challenges like component slippage and corrosion-induced failure. The Black-Oxide Alloy Steel construction provides a protective layer that minimizes rust in humid or abrasive settings, while the Rockwell C45 hardness ensures the screw maintains its integrity under repetitive stress. Its headless design with a hex drive allows for flush installation in machinery, pulleys, and gears, preventing interference and offering a clean finish. The cup tip digs securely into shafts, making it ideal for positioning and locking applications in automotive, aerospace, and manufacturing assemblies where precision and reliability are non-negotiable.

Specification Summary & Compliance

This set screw adheres to Class 3A thread fit for tight tolerances and UNC coarse threading with a 4-40 size and 0.112" diameter. It conforms to ASME B18.3 manufacturing specifications and is compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) regulations, ensuring environmental safety and material reliability.