S-91375A124 5-40 x 1/4" 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.
• Exceptional holding power from Rockwell C45 hardness, preventing stripping and maintaining clamp force under vibration.
• Precise, reliable engagement with Class 3A thread fit, ensuring consistent performance in high-tolerance assemblies.
• Secure, high-torque installation using the 1/16" hex drive, minimizing cam-out and tool wear.
• Effective component positioning with the cup tip design, providing positive contact and reducing workpiece marring.
• Broad industry compatibility through UNC coarse threading, facilitating faster assembly and disassembly.
• Regulatory peace of mind with compliance to ASME B18.3, RoHS 3, and REACH standards.

Professional Applications & Engineering Value

Engineered for precision-locking applications, these 5-40 UNC set screws provide a robust solution for securing collars, gears, and pulleys on shafts. The black-oxide alloy steel construction offers enhanced resistance to rust and wear, critical in machinery exposed to oils and moderate moisture. The Class 3A thread fit and coarse UNC thread ensure rapid, secure fastening while maintaining alignment in high-vibration environments like motors and power transmission systems. The headless design and cup tip allow for flush mounting and concentrated clamping force, preventing component slippage without damaging shaft surfaces. Ideal for OEM and MRO applications demanding repeatable, reliable performance.

Specification Summary & Compliance

This set screw adheres to ASME B18.3 dimensional standards with a Class 3A thread fit for precise tolerance. The UNC coarse thread (5-40) and right-hand direction ensure industry-standard compatibility. Manufacturing and material compliance include RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) environmental regulations, confirming the absence of restricted hazardous substances.