S-91251A639 3/8"-16 x 3 3/4" ASTM A574 Alloy Steel Socket Head Screws

Key Features & Benefits at a Glance

• Exceptional strength and durability with 170,000 psi tensile strength and Rockwell C37 hardness, ideal for high-stress industrial environments.
• Superior corrosion resistance thanks to the black-oxide coating on alloy steel, extending service life in demanding conditions.
• Precise and reliable fastening with Class 3A thread fit, ensuring tight tolerances and reduced risk of loosening under vibration.
• Easy installation and high torque capability via the 5/16" hex drive and standard socket head, allowing for secure tightening in confined spaces.
• Optimized for heavy-duty applications featuring coarse 3/8"-16 UNC threads and a 3 3/4" length for robust connections in machinery and equipment.
• Compliance with industry standards including ASTM A574, ensuring consistent quality and performance in professional settings.
• Environmentally responsible manufacturing with RoHS 3 and REACH compliance, meeting global regulatory requirements for safe use.

Professional Applications & Engineering Value

This Socket Head Cap Screw is engineered from black-oxide alloy steel to address common industrial challenges such as corrosion, high tensile stress, and vibration-induced failure. The coarse UNC threads and Class 3A thread fit provide excellent grip and alignment in heavy machinery, automotive assemblies, and construction equipment, minimizing the need for frequent maintenance. Its partially threaded design and hex drive allow for efficient installation in tight spaces, enhancing productivity in manufacturing and repair operations. By combining high tensile strength with reliable surface treatment, this fastener delivers long-term performance in demanding environments, reducing downtime and total cost of ownership.

Specification Summary & Compliance

This product features precise Class 3A thread fit with 3/8"-16 UNC coarse threads and a minimum thread length of 1 1/4". It complies with ASTM A574 specifications for socket head cap screws and meets RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) environmental standards, ensuring safety and regulatory adherence in industrial applications.