S-91375A551 1/4"-20 x 2 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 hardened alloy steel, preventing stripping under high torque.
• Precise and secure fastening with Class 3A thread fit, ensuring minimal backlash and reliable positioning.
• Easy installation in confined spaces using the headless hex socket design with a 1/8" drive.
• Enhanced grip on shafts and components from the cup tip design, reducing slippage in dynamic applications.
• Wide compatibility with UNC coarse threads (1/4"-20), facilitating quick assembly and disassembly.
• Compliance with major industry standards including ASME B18.3, ensuring consistent quality and safety.

Professional Applications & Engineering Value

This black-oxide alloy steel set screw is engineered to address critical challenges in industrial machinery and equipment assembly. The headless design with a hex socket drive allows for flush mounting in tight spaces, eliminating protrusions that could interfere with moving parts. Its UNC coarse threads and Class 3A fit provide superior engagement and vibration resistance, making it ideal for securing pulleys, gears, and collars on rotating shafts. The cup tip concentrates pressure on a small contact area, enhancing grip without damaging components. Combined with Rockwell C45 hardness, it ensures long-term reliability in high-stress applications, from automotive systems to heavy-duty manufacturing equipment, reducing maintenance needs and downtime.

Specification Summary & Compliance

This set screw adheres to precise dimensional standards with UNC 1/4"-20 coarse threads and a Class 3A thread fit for tight tolerances. It meets ASME B18.3 specifications for consistent performance and is manufactured in compliance with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) regulations, ensuring environmental safety and material sustainability.