S-91251A626 3/8"-16 x 1 1/4" 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.
• Class 3A thread fit provides precise, tight tolerances for superior thread engagement and vibration resistance, minimizing loosening in dynamic environments.
• Black-oxide surface treatment on alloy steel offers enhanced corrosion resistance, extending service life in harsh industrial settings without compromising dimensional integrity.
• Fully threaded UNC coarse design allows for faster installation and maximum grip length, improving holding power and assembly efficiency.
• Hex socket drive (5/16") enables high-torque application with standard tools, facilitating secure fastening in confined spaces and reducing strip-out risks.
• Rockwell C37 hardness ensures durability and wear resistance, maintaining thread integrity and fastener performance over repeated use.
• Compliance with ASTM A574, RoHS 3, and REACH guarantees material consistency, environmental safety, and suitability for regulated industries.

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 in exposed environments. The UNC coarse thread and Class 3A fit provide excellent resistance to dynamic loads, making it ideal for machinery, automotive, and heavy equipment applications where reliability is paramount. The alloy steel construction with a black-oxide finish combats rust and wear, while the fully threaded design ensures uniform stress distribution. These features deliver long-term value by reducing maintenance needs and enhancing the structural integrity of assembled components.

Specification Summary & Compliance

This socket head cap screw adheres to Class 3A thread fit for precise UNC coarse threading (3/8"-16), ensuring dimensional accuracy per industry standards. It meets ASTM A574 specifications for material and manufacturing quality, and is compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) regulations, confirming its suitability for environmentally conscious and regulated industrial use.