S-90289A361 5/16"-24 x 1/2" ASME B18.3 Set Screws

Key Features & Benefits at a Glance

• Enhanced corrosion resistance with black-oxide coating, extending service life in demanding industrial environments.
• Superior thread engagement and holding power from UNF Class 3A fine threads, ensuring reliable, vibration-resistant connections.
• High-strength performance backed by Rockwell C45 hardness, providing excellent resistance to wear and deformation.
• Secure, non-slip fastening with the hex 5/32" drive and serrations, allowing for high torque application and preventing loosening.
• Precise component positioning using the cup tip design, which minimizes surface damage and offers concentrated clamping force.
• Space-saving headless design ideal for applications where flush mounting or limited clearance is required.
• Guaranteed reliability and compliance with ASME B18.3 standards, RoHS 3, and REACH, ensuring material safety and performance consistency.

Professional Applications & Engineering Value

This black-oxide alloy steel set screw is engineered to address critical challenges in industrial assembly, such as vibration-induced loosening and component misalignment. The UNF Class 3A fine threads provide a tighter fit and higher tensile strength compared to coarse threads, making them ideal for precision machinery, automotive components, and electronic enclosures where secure fastening is paramount. The cup tip concentrates force on a small area, reducing the risk of damage to shafts or collars, while the hex drive allows for easy installation in confined spaces. With its headless design and serrations for locking, this screw ensures a permanent, flush fit that withstands dynamic loads, making it a trusted solution for engineers seeking durability and compliance in demanding applications.

Specification Summary & Compliance

This set screw adheres to ASME B18.3 specifications, ensuring dimensional accuracy and performance reliability. The thread fit is Class 3A, providing a high-precision tolerance for superior engagement in UNF fine threads (5/16"-24). It is fully compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) regulations, confirming the use of safe, environmentally responsible materials. Manufactured from alloy steel with a black-oxide surface treatment, it meets industrial standards for strength and corrosion resistance, supporting consistent performance in right-hand thread applications.