S-91251A079 2-56 x 3/8" 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 failure risks in demanding applications.
• Precision Class 3A thread fit provides superior engagement and vibration resistance, maintaining secure fastening in dynamic environments.
• Black-oxide coating on alloy steel offers enhanced corrosion resistance and a durable finish, extending service life in harsh industrial settings.
• Fully threaded right-hand UNC coarse design allows for quick installation and maximum grip across the entire length, improving assembly efficiency.
• Rockwell C37 hardness delivers excellent wear resistance, minimizing deformation and ensuring long-term fastener integrity.
• Standard hex socket drive (5/64") enables easy torque application with common tools, reducing installation time and tool wear.
• Compliance with ASTM A574, RoHS 3, and REACH guarantees adherence to industry standards for safety and environmental responsibility, supporting global supply chain requirements.

Professional Applications & Engineering Value

This Black-Oxide Alloy Steel Socket Head Cap Screw is engineered to address critical challenges in precision assembly and heavy-duty machinery. The 2-56 UNC coarse thread with Class 3A fit ensures tight tolerances and reliable performance in applications prone to vibration, such as automotive components, aerospace systems, and industrial equipment. The fully threaded right-hand design maximizes load distribution, reducing stress concentrations that lead to fatigue failures. Combined with a 170,000 psi tensile strength and Rockwell C37 hardness, it provides durability in high-temperature or corrosive environments, while the black-oxide surface treatment enhances resistance to rust and wear. Ideal for precision fasteners in OEM and MRO settings, this screw delivers consistent performance, minimizes maintenance downtime, and supports compliance with stringent industry regulations.

Specification Summary & Compliance

This product features precise inch system measurements with a Thread Fit of Class 3A and UNC coarse thread spacing, ensuring accurate engagement and dimensional stability. It meets ASTM A574 specifications for high-strength socket head cap screws, guaranteeing material and manufacturing consistency. Additionally, it is RoHS 3 (2015/863/EU) Compliant and REACH (EC 1907/2006) Compliant, confirming adherence to environmental and safety standards for hazardous substances, making it suitable for global industrial use.