S-91251A023 1 1/4"-7 x 9" ASTM A574 Alloy Steel Socket Head Screws

Key Features & Benefits at a Glance

• Superior tensile strength of 170,000 psi ensures reliable performance under extreme loads, minimizing the risk of fastener failure in demanding applications.
• Exceptional durability and wear resistance from Rockwell C37 hardness, providing a long service life even in high-stress environments.
• Enhanced corrosion protection with the black-oxide finish, offering improved resistance to rust and oxidation for extended use in various industrial conditions.
• Secure and efficient installation with the 7/8" hex drive and standard socket head, allowing for high torque application and reduced slipping.
• Optimized thread engagement through coarse 1 1/4"-7 UNRC threads and Class 2A fit, facilitating quicker assembly and robust connections.
• Versatile partial threading design allows for precise clamping force control, ideal for applications requiring specific unthreaded shaft sections.
• Full regulatory compliance with ASTM A574, RoHS 3, and REACH standards, ensuring material quality and environmental safety for global industrial use.

Professional Applications & Engineering Value

This black-oxide alloy steel socket head cap screw is engineered to address critical challenges in heavy machinery, construction, and automotive assemblies where high tensile strength and corrosion resistance are paramount. The coarse UNRC thread and Class 2A fit ensure rapid, secure fastening in structural applications, reducing installation time and preventing loosening under vibration. The partially threaded design with a minimum thread length of 3 1/8" provides flexibility for precise joint clamping, while the 7/8" hex drive enables high-torque tightening without tool slippage. Ideal for industrial fastening in harsh environments, it combines 170,000 psi tensile strength and Rockwell C37 hardness to withstand dynamic loads and prolong equipment lifespan, meeting rigorous ASTM A574 specifications for reliability.

Specification Summary & Compliance

This socket head cap screw features precise 1 1/4"-7 coarse UNRC threads with a Class 2A thread fit for consistent dimensional accuracy and ease of assembly. Manufactured in compliance with ASTM A574 for material and mechanical properties, it also adheres to RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) regulations, ensuring environmental safety and suitability for global industrial markets. The product meets all specified standards for tensile strength, hardness, and finish, guaranteeing performance in demanding applications.