S-91251A588 3/8"-16 x 1 1/8" 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 from the black-oxide finish protects against rust and environmental damage, extending service life in harsh industrial environments.
• Precision Class 3A thread fit guarantees tight tolerances and secure fastening, minimizing loosening and vibration-related issues.
• High hardness (Rockwell C37) provides excellent wear resistance, maintaining thread integrity and drive engagement through repeated use.
• Hex socket drive design allows for high-torque installation with standard tools, enabling efficient assembly in confined spaces.
• Full threading offers consistent grip along the entire length, providing versatile clamping force distribution.
• Compliance with ASTM A574, RoHS 3, and REACH ensures 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 precision machinery, automotive assemblies, and heavy-duty equipment. The 3/8"-16 coarse UNRC thread with Class 3A fit ensures rapid installation and vibration resistance, reducing maintenance downtime. The alloy steel construction combined with 170,000 psi tensile strength provides exceptional load-bearing capacity, preventing shear and tensile failures in high-stress joints. The black-oxide surface treatment enhances corrosion resistance without compromising dimensional accuracy, making it ideal for applications exposed to moisture, chemicals, or outdoor conditions. Its hex drive and fully threaded design facilitate secure fastening in tight spaces, improving assembly efficiency and reliability in automated production lines.

Specification Summary & Compliance

This socket head cap screw features a 3/8"-16 coarse thread with Class 3A precision fit per UNRC standards, ensuring consistent threading and secure engagement. Manufactured to ASTM A574 specifications, it guarantees material integrity and performance reliability. The product is fully compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) regulations, adhering to environmental and safety standards for industrial use.