S-90289A541 1/4"-20 x 7/8" ASME B18.3 Set Screws

Key Features & Benefits at a Glance

• Superior corrosion resistance with black-oxide coating, extending service life in harsh industrial environments
• Exceptional holding power from Class 3A thread fit, ensuring precise, vibration-resistant fastening
• High-strength durability with Rockwell C45 hardness, providing reliable performance under heavy loads
• Secure installation using hex drive design, allowing high torque application without head protrusion
• Enhanced grip from cup tip and serrations, preventing component slippage in dynamic applications
• Industry-standard compatibility with UNC coarse threads, facilitating easy replacement and maintenance
• Regulatory compliance meeting ASME B18.3, RoHS, and REACH standards for global industrial use

Professional Applications & Engineering Value

This black-oxide alloy steel set screw delivers critical engineering solutions for industrial machinery, automotive assemblies, and precision equipment. The Class 3A UNC coarse thread provides superior engagement in soft materials and rapid installation, while the headless hex drive design enables flush mounting in space-constrained applications. The Rockwell C45 hardness ensures maintained clamping force under vibration and thermal cycling, preventing joint failure. Combined with serrations and cup tip, it offers maximum resistance to rotational loosening in high-torque environments, making it ideal for permanent positioning of gears, pulleys, and collars on shafts.

Specification Summary & Compliance

Manufactured to ASME B18.3 specifications with 1/4"-20 UNC coarse threads and Class 3A thread fit for precision tolerance. The 7/8" length and 1/8" hex drive provide standardized dimensions for consistent performance. Fully compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) environmental regulations, ensuring safe use in global industrial markets.