S-91251A025 1 1/4"-7 x 11" 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 extends service life in harsh environments, minimizing maintenance and replacement costs.
• High hardness rating (Rockwell C37) provides excellent wear resistance, maintaining thread integrity and drive engagement over repeated use.
• Coarse UNRC thread design allows for quicker installation and better performance in materials where fine threads may strip or fail.
• Partially threaded shank offers precise clamping force control, ideal for applications requiring specific grip lengths without thread interference.
• Large 7/8" hex drive enables high torque application with standard tools, ensuring secure fastening and reducing installation time.
• Compliance with ASTM A574 guarantees consistent quality and mechanical properties, providing peace of mind for critical engineering projects.

Professional Applications & Engineering Value

This black-oxide alloy steel socket head cap screw is engineered to address common industrial challenges such as vibration loosening, corrosion-induced degradation, and high-load fatigue. The coarse UNRC thread and Class 2A thread fit ensure reliable engagement in soft materials or where rapid assembly is required, while the partially threaded design prevents thread damage in through-holes. Ideal for heavy machinery, construction equipment, and automotive assemblies, its 170,000 psi tensile strength and Rockwell C37 hardness provide a durable solution for dynamic load applications, reducing downtime and maintenance cycles in demanding environments.

Specification Summary & Compliance

This socket head cap screw features a 1 1/4"-7 coarse UNRC thread with Class 2A thread fit for standard industrial tolerances. Manufactured to ASTM A574 specifications, it ensures consistent mechanical properties and dimensional accuracy. The product is fully compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) regulations, supporting environmentally responsible sourcing and usage in global markets.