S-90289A125 5-40 x 5/16" ASME B18.3 Set Screws

Key Features & Benefits at a Glance

• Superior holding power with Class 3A thread fit ensuring tight, reliable fastening in demanding applications
• Exceptional durability from Rockwell C45 hardened black-oxide alloy steel resisting wear and corrosion
• Secure installation with 1/16" hex drive providing positive torque control in confined spaces
• Enhanced grip from cup point design concentrating pressure for maximum resistance to loosening
• Industry compliance meeting ASME B18.3 specifications for consistent performance and interchangeability
• Environmental responsibility with RoHS 3 and REACH compliance for safe use in regulated industries
• Optimized engagement through coarse UNC threads enabling faster assembly and reduced cross-threading risk

Professional Applications & Engineering Value

This 5-40 UNC set screw delivers critical engineering solutions where vibration resistance and permanent positioning are paramount. The black-oxide alloy steel construction with Rockwell C45 hardness maintains integrity under stress, while the cup point creates permanent dimples in shafts and collars for slip-free performance. The headless design with 1/16" hex drive allows flush mounting in space-constrained assemblies, making it ideal for precision machinery, motor collars, and gear assemblies. Class 3A thread fit and coarse UNC threads ensure rapid installation with minimal galling, reducing assembly time in high-volume production environments.

Specification Summary & Compliance

Manufactured to ASME B18.3 standards with Class 3A thread fit precision and UNC coarse threads (5-40). Full compliance with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) environmental regulations. Material specifications include black-oxide coated alloy steel with Rockwell C45 hardness, right-hand thread direction, and serrations for enhanced locking performance.