S-90289A121 5-40 x 1/8" 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 due to Class 3A thread fit, ensuring precise, vibration-resistant fastening.
• High-strength durability from alloy steel and Rockwell C45 hardness, resisting deformation under load.
• Secure anti-rotation locking via serrations, preventing loosening in dynamic applications.
• Easy installation and removal with 1/16" hex drive, allowing efficient maintenance in confined spaces.
• Effective surface grip from cup tip design, minimizing damage to shafts and components.
• Reliable compliance with ASME B18.3, RoHS 3, and REACH, ensuring safety and regulatory adherence.

Professional Applications & Engineering Value

This 5-40 UNC set screw is engineered to address critical industrial challenges, such as component slippage and corrosion-induced failure. The black-oxide alloy steel construction provides a robust barrier against moisture and chemicals, ideal for machinery, automotive, and electrical assemblies exposed to demanding conditions. With a coarse thread and Class 3A thread fit, it delivers tight tolerances and reliable clamping force, reducing the risk of vibration loosening in high-stress environments. The headless design and cup tip ensure flush mounting and secure contact, protecting aligned parts from damage. Compliant with ASME B18.3 standards, it guarantees consistency for precision engineering and B2B procurement needs.

Specification Summary & Compliance

This set screw adheres to Class 3A thread fit for high precision in UNC coarse threads, with a thread size of 5-40 and diameter of 0.125". Manufactured under ASME B18.3 specifications, it ensures dimensional accuracy and performance reliability. The product is fully RoHS 3 (2015/863/EU) Compliant and REACH (EC 1907/2006) Compliant, meeting environmental and safety regulations for industrial use.