S-91375A574 5/16"-18 x 1/4" ASME B18.3, ASTM F912 Set Screws

Key Features & Benefits at a Glance

• Exceptional holding power with Class 3A thread fit for secure, vibration-resistant fastening in demanding applications
• Superior corrosion resistance from the black-oxide finish on alloy steel, extending service life in harsh industrial environments
• High-strength durability with Rockwell C45 hardness, resisting deformation under heavy loads and repeated use
• Reliable installation and removal using the 5/32" hex drive, providing a secure tool grip and reducing slippage risks
• Effective surface gripping with the cup tip design, minimizing component damage while ensuring firm positioning
• Wide compatibility with UNC coarse threads (5/16"-18), facilitating quick assembly and interchangeability in standard systems
• Space-saving headless design allowing flush mounting where protruding fasteners are not feasible

Professional Applications & Engineering Value

This 5/16"-18 UNC set screw is engineered to address critical challenges in industrial assembly, such as component slippage and vibrational loosening. The black-oxide alloy steel construction offers enhanced corrosion protection, making it suitable for machinery, automotive, and equipment manufacturing where exposure to moisture and chemicals is common. Its Class 3A thread fit ensures precise engagement with mating parts, reducing the risk of cross-threading and providing consistent clamping force. The hex drive and cup tip work in tandem to enable easy installation with standard tools while creating a firm grip on shafts, collars, and pulleys. Ideal for permanent or semi-permanent fastening, this headless set screw delivers reliable performance in high-stress applications, from conveyor systems to precision instruments, ensuring long-term operational stability.

Specification Summary & Compliance

This set screw adheres to UNC coarse thread standards with a 5/16"-18 thread size and Class 3A thread fit for superior dimensional accuracy. It meets ASME B18.3 and ASTM F912 specifications, ensuring consistent manufacturing quality. The product is fully compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) regulations, confirming its safety for use in regulated industries without hazardous substances.