S-91375A430 5/8"-18 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 demanding industrial environments.
• Exceptional holding power provided by Class 3A thread fit, ensuring minimal backlash and reliable, vibration-resistant connections.
• High-strength durability from alloy steel heat-treated to Rockwell C45 hardness, resisting wear and deformation under heavy loads.
• Secure, flush mounting enabled by the headless design and cup tip, preventing component interference and providing concentrated clamping force.
• Easy installation and high torque application with the 5/16" hex drive, allowing for efficient assembly with standard tools.
• Precise engagement in fine-threaded components due to the 5/8"-18 UNF fine thread, ideal for applications requiring accurate adjustment.
• Broad regulatory compliance meeting ASME B18.3, ASTM F912, RoHS 3, and REACH, ensuring suitability for regulated and international markets.

Professional Applications & Engineering Value

This black-oxide alloy steel set screw is engineered to solve critical fastening challenges in precision machinery, automotive assemblies, and heavy-duty equipment. The headless design and cup tip provide a flush finish and concentrated point pressure, preventing loosening from vibrations and securing components like gears, pulleys, and collars onto shafts without protruding parts. The Class 3A thread fit with UNF fine threads offers superior engagement in tapped holes, reducing the risk of cross-threading and ensuring accurate positional control. Made from high-strength alloy steel with a Rockwell C45 hardness, it withstands high shear and tensile stresses, making it a reliable choice for permanent or semi-permanent applications where disassembly is infrequent. The hex drive allows for high torque installation, ensuring a secure fit in confined spaces.

Specification Summary & Compliance

This set screw features a 5/8"-18 UNF thread with a Class 3A fit, ensuring tight tolerances and precise thread engagement for high-strength applications. It is manufactured in accordance with ASME B18.3 and ASTM F912 specifications, guaranteeing consistent quality and performance. The product is fully compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) regulations, confirming its adherence to environmental and safety standards for hazardous substances.