S-91375A171 4-40 x 1" ASME B18.3, ASTM F912 Set Screws

Key Features & Benefits at a Glance

• Superior corrosion resistance with black-oxide coating, extending service life in demanding industrial environments
• Precise Class 3A thread fit ensures secure fastening with minimal backlash in critical assemblies
• High-strength alloy steel construction with Rockwell C45 hardness maintains dimensional stability under heavy loads
• Hex drive design provides maximum torque transmission while preventing tool slippage during installation
• Cup tip configuration creates deep indentation on shafts for permanent positioning without loosening
• Full regulatory compliance meets ASME B18.3, RoHS 3, and REACH standards for global industrial applications
• Coarse UNC threading enables rapid installation and removal while maintaining holding strength

Professional Applications & Engineering Value

Engineered for precision positioning and permanent fastening in industrial machinery, this 4-40 UNC set screw delivers exceptional performance in demanding applications. The black-oxide alloy steel construction provides superior corrosion protection while maintaining Rockwell C45 hardness for repeated adjustment cycles without deformation. The Class 3A thread fit ensures tight tolerances for vibration-resistant assemblies in motors, gears, and coupling systems. The cup tip design creates secure dimpling on shafts and collars, preventing rotational slippage in high-torque environments. Ideal for manufacturing equipment, automotive components, and precision instruments where reliable positioning is critical.

Specification Summary & Compliance

This headless set screw features precise 4-40 UNC coarse threads with Class 3A thread fit per ASME B18.3 specifications. Manufacturing complies with ASTM F912 standards, ensuring dimensional accuracy and mechanical properties. The component is fully RoHS 3 (2015/863/EU) Compliant and REACH (EC 1907/2006) Compliant, meeting international environmental regulations for industrial use.