S-91251A621 3/8"-16 x 5/8" ASTM A574 Alloy Steel Socket Head Screws

Key Features & Benefits at a Glance

• Exceptional tensile strength of 170,000 psi ensures reliable performance under high-stress conditions, reducing the risk of fastener failure in demanding applications.
• Superior corrosion resistance provided by the black-oxide finish on alloy steel, extending service life in harsh industrial environments.
• Precise Class 3A thread fit guarantees secure, vibration-resistant connections, minimizing loosening in machinery and equipment.
• Hex socket drive design allows for high-torque installation with standard tools, facilitating quick assembly and maintenance.
• Coarse UNC threads enable faster installation and better debris resistance compared to fine threads, saving time in production settings.
• Full threading along the 5/8" length offers versatile positioning and adjustment flexibility in assembled components.
• Compliance with ASTM A574 ensures consistent quality and mechanical properties, meeting rigorous industrial standards.

Professional Applications & Engineering Value

This black-oxide alloy steel socket head cap screw is engineered to address critical challenges in industrial assembly, such as vibration-induced loosening and corrosion. The 3/8"-16 UNC coarse thread with Class 3A fit provides excellent grip and resistance to shaking, making it ideal for heavy machinery, automotive systems, and precision equipment. The hex drive allows for efficient installation in confined spaces, while the high tensile strength and Rockwell C37 hardness ensure durability under dynamic loads. By combining robust materials with precise manufacturing, this fastener reduces maintenance downtime and enhances the longevity of mechanical connections in demanding environments.

Specification Summary & Compliance

This socket head cap screw features a 3/8"-16 UNC coarse thread with Class 3A tolerance for precise fit, and is fully threaded along its 5/8" length. It meets ASTM A574 specifications for material and mechanical properties, ensuring consistent performance. The product is compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) regulations, supporting environmentally responsible sourcing and usage in global markets.