S-91375A744 1/2"-20 x 3" ASME B18.3, ASTM F912 Set Screws

Key Features & Benefits at a Glance

• Superior corrosion resistance with black-oxide coating, extending service life in harsh industrial environments
• Exceptional thread precision with Class 3A fit ensures vibration-resistant, secure fastening in critical applications
• High-strength performance from Rockwell C45 hardened alloy steel prevents stripping and deformation under heavy loads
• Secure installation and removal with 1/4" hex drive design, providing reliable torque transmission without head protrusion
• Enhanced grip and positioning with cup tip design that minimizes component surface damage during clamping
• Optimized for fine-thread applications with 1/2"-20 UNF threading, delivering superior resistance to loosening in dynamic loads
• Full regulatory compliance meeting ASME B18.3, RoHS 3, and REACH standards for global industrial use

Professional Applications & Engineering Value

This black-oxide alloy steel set screw delivers critical engineering solutions for demanding industrial applications where vibration resistance, precise alignment, and long-term reliability are paramount. The Class 3A thread fit with UNF fine threads provides exceptional clamping force retention in machinery, automotive components, and precision equipment, preventing costly downtime from fastener failure. The combination of Rockwell C45 hardness and corrosion-resistant black-oxide surface treatment ensures durability in both indoor and outdoor environments, while the headless design with 1/4" hex drive allows for flush mounting in space-constrained assemblies. These set screws are engineered to maintain positional accuracy in rotating shafts, gears, and pulleys where secure fastening is critical to operational safety and performance.

Specification Summary & Compliance

This precision fastener features 1/2"-20 UNF fine threads with Class 3A thread fit for superior dimensional accuracy and tight tolerances. Manufacturing complies with ASME B18.3 specifications (referencing ASTM F912) ensuring consistent quality and performance. The product is fully compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) regulations, meeting the latest environmental standards for industrial use. Thread direction is right-hand with cup tip configuration, and the 3" length provides ample engagement for secure fastening in various applications.