S-91251A651 3/8"-16 x 5 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 in high-stress industrial applications, reducing the risk of fastener failure.
• Superior corrosion resistance from the black-oxide finish on alloy steel, extending service life in harsh environments and minimizing maintenance needs.
• Precision Class 3A thread fit provides tight tolerances for secure, vibration-resistant assemblies, enhancing joint integrity.
• High hardness rating (Rockwell C37) offers excellent wear resistance, maintaining thread integrity through repeated use.
• Partially threaded design allows for controlled clamping force and easier alignment in assemblies, improving installation efficiency.
• Standard hex drive (5/16") enables easy installation with common tools, reducing assembly time and labor costs.
• Compliance with ASTM A574, RoHS 3, and REACH ensures material quality and environmental safety, meeting global regulatory standards for industrial use.

Professional Applications & Engineering Value

This Black-Oxide Alloy Steel Socket Head Cap Screw is engineered to address critical challenges in heavy-duty applications, such as machinery assembly, automotive systems, and construction equipment. The 3/8"-16 UNC coarse thread and Class 3A fit provide superior grip and vibration resistance, preventing loosening under dynamic loads. Made from high-strength alloy steel with a protective black-oxide coating, it combats corrosion and wear in demanding environments, reducing downtime and replacement costs. Ideal for industrial fasteners requiring precise torque and durability, this screw ensures long-term reliability in partially threaded configurations, offering optimal clamping force without compromising structural integrity.

Specification Summary & Compliance

This socket head cap screw features precise inch system measurements, including a 5-1/4" length and 3/8"-16 UNC thread with Class 3A thread fit for tight tolerances. It complies with ASTM A574 specifications for high-strength fasteners, ensuring consistent quality and performance. Additionally, it meets RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) compliance, supporting environmentally safe and regulated industrial use.