S-90289A106 4-40 x 1/4" ASME B18.3 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 Class 3A thread fit, ensuring vibration-resistant, secure fastening in critical assemblies
• High-strength durability with Rockwell C45 hardness alloy steel, resisting deformation under heavy loads
• Secure anti-rotation locking through serrations, preventing loosening in high-vibration applications
• Easy installation and removal with hex drive design, allowing efficient maintenance with standard tools
• Effective surface grip from cup tip design, minimizing component slippage on shafts or hubs
• Reliable coarse UNC threading for quick assembly and disassembly in time-sensitive operations

Professional Applications & Engineering Value

This 4-40 UNC set screw delivers precision engineering for industrial applications requiring reliable shaft and component positioning. The black-oxide alloy steel construction provides enhanced corrosion resistance, while the Rockwell C45 hardness ensures the fastener maintains its integrity under repetitive stress. The combination of hex drive and serrations addresses common vibration-induced loosening issues in machinery, automotive, and aerospace assemblies. With its cup tip design, it offers superior gripping force on rotating components, making it ideal for permanent or semi-permanent fastening solutions where disassembly is infrequent but must be reliable when required.

Specification Summary & Compliance

Manufactured to ASME B18.3 specifications with Class 3A thread fit for precise dimensional accuracy. The UNC coarse thread (4-40) and right-hand direction ensure compatibility with standard components. Compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) environmental regulations, meeting global industrial standards for safe and sustainable use.