S-91251A944 1 1/4"-7 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, reducing the risk of fastener failure in critical applications.
• Superior corrosion resistance provided by the black-oxide finish on alloy steel, extending service life in demanding industrial environments.
• High torque capability with a 7/8" hex drive and standard socket head profile, allowing for secure installation and removal with common tools.
• Optimized thread engagement through a coarse 1 1/4"-7 UNRC thread and Class 2A fit, facilitating quicker assembly and robust holding power.
• Enhanced durability from Rockwell C37 hardness, maintaining structural integrity and resistance to wear over repeated use.
• Versatile partial threading on a 6" length, offering flexibility for applications requiring both threaded and unthreaded sections.
• Compliance with major standards including ASTM A574, RoHS 3, and REACH, ensuring material quality and environmental safety for global supply chains.

Professional Applications & Engineering Value

This black-oxide alloy steel socket head cap screw is engineered to address common industrial challenges such as vibration loosening and corrosion in heavy machinery, construction equipment, and automotive assemblies. The coarse UNRC thread and Class 2A fit provide excellent resistance to cross-threading and ensure consistent clamping force, reducing maintenance downtime. With a 1 1/4"-7 thread size and partially threaded design, it is ideal for applications requiring precise alignment and high shear strength, such as in structural frames and hydraulic systems. The combination of 170,000 psi tensile strength and Rockwell C37 hardness delivers reliable performance in high-stress environments, while the black-oxide surface treatment enhances corrosion resistance without compromising dimensional stability.

Specification Summary & Compliance

This socket head cap screw features a 1 1/4"-7 coarse thread with Class 2A tolerance for precise fit and ease of assembly. It meets ASTM A574 specifications for high-strength alloy steel fasteners, ensuring consistent material properties and manufacturing quality. The product is fully compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) regulations, confirming its adherence to environmental and safety standards for industrial use.