S-90289A124 5-40 x 1/4" ASME B18.3 Set Screws

Key Features & Benefits at a Glance

• Superior corrosion resistance with black-oxide coating on alloy steel for extended service life in harsh industrial environments
• Exceptional holding power achieved through Class 3A thread fit precision and serrations that prevent rotational slippage
• High-strength performance backed by Rockwell C45 hardness rating for reliable operation under heavy loads
• Space-saving headless design with hex drive allows installation in confined spaces while maintaining secure fastening
• Enhanced grip and alignment from cup tip design that provides positive seating on mating surfaces
• Quick installation and removal with 1/16" hex drive that accommodates standard tools for efficient maintenance
• Reliable coarse threading with UNC 5-40 specification ensures rapid assembly and strong engagement in various materials

Professional Applications & Engineering Value

This 5-40 UNC set screw delivers critical engineering solutions for industrial applications requiring precision alignment and permanent positioning. The black-oxide alloy steel construction provides excellent corrosion protection while maintaining the Rockwell C45 hardness needed for high-stress environments. The combination of Class 3A thread fit and serrations locking mechanism creates unparalleled resistance to vibration-induced loosening in machinery, automotive components, and precision equipment. The headless design with hex drive enables flush mounting in space-constrained assemblies, while the cup tip ensures maximum surface contact for secure fastening of gears, pulleys, and collars onto shafts. These industrial set screws are engineered to maintain critical alignments in manufacturing equipment, robotics, and power transmission systems where reliability is paramount.

Specification Summary & Compliance

This precision fastener features 5-40 UNC coarse threads with Class 3A thread fit for superior dimensional accuracy and engagement. The 1/4" length and 0.125" thread diameter provide consistent performance across applications. Manufactured in compliance with ASME B18.3 standards for dimensional consistency and mechanical properties. Meets RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) environmental regulations, ensuring safe use in regulated industries and international markets.