S-91251A938 1 1/4"-7 x 3" 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, reducing the risk of fastener failure in critical applications.
• Superior corrosion resistance from the black-oxide finish prolongs service life in harsh industrial environments, minimizing maintenance and replacement costs.
• High hardness (Rockwell C37) provides excellent wear resistance, maintaining thread integrity and drive engagement through repeated use.
• 7/8" hex drive design allows for high torque application with standard tools, ensuring secure fastening and reducing installation time.
• Class 2A thread fit with UNRC coarse threads offers easier assembly and better tolerance to minor debris, improving efficiency in production lines.
• Fully threaded construction enables consistent clamping force along the entire length, ideal for adjustable or deep-set applications.
• Compliance with ASTM A574, RoHS 3, and REACH guarantees material consistency and environmental safety, meeting global industrial standards.

Professional Applications & Engineering Value

This black-oxide alloy steel socket head cap screw is engineered to address common challenges in heavy machinery, automotive, and construction sectors where vibration, high stress, and environmental exposure are concerns. The UNRC coarse thread design resists loosening under dynamic loads, while the fully threaded shank allows for precise adjustment in assemblies requiring variable grip lengths. The corrosion-resistant black-oxide coating protects against rust and chemical degradation, extending component life in outdoor or humid conditions. With a high-strength profile and standard hex drive, it simplifies maintenance and reduces downtime, making it a reliable choice for engineers seeking durability and compliance in industrial fastening solutions.

Specification Summary & Compliance

This socket head cap screw features precise Class 2A thread fit with 1 1/4"-7 UNRC coarse threads and right-hand orientation, ensuring consistent engagement and assembly accuracy. Manufactured in accordance with ASTM A574 specifications, it meets rigorous material and performance standards. The product is fully compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) regulations, confirming its suitability for use in environmentally conscious and regulated industries.