S-91251A773 1 3/8"-6 x 6" ASTM A574 Alloy Steel Socket Head Screws

Key Features & Benefits at a Glance

• Exceptional tensile strength of 170,000 psi ensures reliable performance under extreme loads and prevents fastener failure in demanding applications.
• Superior corrosion resistance from the black-oxide finish on alloy steel, extending service life and reducing maintenance in harsh industrial environments.
• Optimized torque transmission via the 1" hex drive and standard socket head profile, allowing for secure installation and high clamping force.
• Robust thread engagement with coarse 1 3/8"-6 UNC threads and Class 2A fit provides vibration resistance and simplifies alignment in heavy machinery.
• Enhanced durability from Rockwell C37 hardness, offering excellent wear resistance and long-term reliability for repetitive use.
• Versatile partial threading on a 6" length allows for precise adjustment and secure fastening in a wide range of assembly configurations.
• Guaranteed compliance with ASTM A574, RoHS 3, and REACH standards, ensuring material consistency and environmental safety for global supply chains.

Professional Applications & Engineering Value

This black-oxide alloy steel socket head cap screw is engineered to address critical challenges in heavy-duty industrial settings. The combination of high tensile strength (170,000 psi) and Rockwell C37 hardness makes it ideal for applications subjected to intense vibration and dynamic loads, such as in construction machinery, automotive jigs, and large-scale manufacturing equipment. The 1 3/8"-6 UNC coarse threads and Class 2A thread fit ensure quick assembly and reliable holding power, reducing the risk of loosening over time. The 1" hex drive facilitates high-torque installation without stripping, while the partial threading offers flexibility for components requiring unthreaded shank sections. This socket head cap screw delivers consistent performance in environments where failure is not an option, providing peace of mind for engineers and procurement specialists.

Specification Summary & Compliance

This product features precise Class 2A thread fit and adheres to UNC coarse thread standards for consistent performance. Manufacturing and material specifications strictly comply with ASTM A574, ensuring high-quality alloy steel construction. The screw is fully compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) regulations, confirming its suitability for use in regulated industries and international markets without hazardous substance restrictions.