S-91385A152 4-40 x 1/8" ASME B18.3, ASTM F912 Set Screws

Key Features & Benefits at a Glance

• Superior vibration resistance with nylon patch thread locker that maintains secure fastening in dynamic applications
• Exceptional corrosion protection through black-oxide coating on alloy steel, extending service life in demanding environments
• Precise torque transmission via 0.050" hex drive, ensuring reliable installation without stripping or cam-out
• Wide temperature tolerance from -50°F to 250°F, maintaining locking performance across industrial operating conditions
• High-strength construction with Rockwell C45 hardness, providing durable thread engagement and resistance to deformation
• Accurate thread engagement with Class 3A fit UNC coarse threads, delivering consistent clamping force and easy assembly
• Space-saving headless design with cup tip for concentrated contact pressure in confined assembly spaces

Professional Applications & Engineering Value

This 4-40 UNC set screw delivers critical engineering solutions for industrial applications requiring reliable shaft positioning and component retention. The black-oxide alloy steel construction combined with Rockwell C45 hardness ensures exceptional durability against wear and fatigue in high-stress assemblies. The integrated nylon patch thread locker effectively prevents loosening from vibration, eliminating the need for secondary locking mechanisms in machinery, automotive components, and precision equipment. The cup tip design concentrates contact pressure for secure fastening of gears, pulleys, and collars while the coarse UNC threads provide rapid installation in production environments. This hex drive set screw addresses common challenges of component slippage and maintenance downtime through its optimized combination of material strength, locking technology, and precision manufacturing.

Specification Summary & Compliance

This set screw maintains Class 3A thread fit per UNC standards with precise dimensional accuracy for consistent performance. Manufactured in compliance with ASME B18.3 specifications, ensuring interchangeability and reliability across industrial applications. The product meets RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) environmental compliance standards, confirming suitability for global industrial markets. The 1/8" length and right-hand thread direction provide standardized installation compatibility while the temperature-resistant nylon patch maintains locking integrity across the specified operational range.