S-91375A541 1/4"-20 x 7/8" 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, extending service life in various industrial environments.
• High-strength durability provided by alloy steel and a Rockwell C45 hardness, resisting wear and deformation.
• Easy installation and removal with a hex drive and 1/8" drive size, allowing for high torque application with standard tools.
• Reliable positioning thanks to the cup tip design, which bites into surfaces to prevent component slippage.
• Broad compatibility with UNC coarse 1/4"-20 threads, a common standard for easy replacement and interchangeability.
• Headless design for a flush finish in confined spaces where protruding fasteners are not feasible.

Professional Applications & Engineering Value

This black-oxide alloy steel set screw is engineered to solve critical challenges in industrial assembly and machinery. The UNC coarse thread and Class 3A fit ensure a tight, precise engagement that resists loosening under vibration, making it ideal for securing pulleys, gears, and collars on shafts. The headless design with a hex drive allows installation in tight spaces without interference, while the cup tip provides excellent grip by creating a small indentation in the mating part. Manufactured from high-strength alloy steel and treated to a Rockwell C45 hardness, it delivers reliable performance in heavy-duty applications, from automotive to manufacturing equipment, ensuring long-term operational integrity.

Specification Summary & Compliance

This set screw features a 1/4"-20 UNC coarse thread with a Class 3A fit for high precision and strength. It meets ASME B18.3 specifications and is compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) regulations, ensuring environmental safety and material reliability for industrial use.