S-91251A945 1 1/4"-7 x 6 1/2" ASTM A574 Alloy Steel Socket Head Screws

Key Features & Benefits at a Glance

• Exceptional tensile strength of 170,000 psi ensures reliable performance under heavy loads and vibration, reducing the risk of fastener failure in demanding applications.
• Superior corrosion resistance from the black-oxide finish on alloy steel, extending service life and maintaining integrity in harsh 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, minimizing stripping.
• Optimized thread engagement using a coarse 1 1/4"-7 UNRC right-hand thread and Class 2A fit, facilitating quicker assembly and better stress distribution.
• Enhanced durability from Rockwell C37 hardness, providing excellent wear resistance and maintaining thread integrity over repeated use.
• Versatile partial threading on a 6 1/2" length offers flexibility for applications requiring precise clamping without full-length threads.
• Compliance with industry 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 critical challenges in heavy machinery, automotive assembly, and construction equipment, where high tensile strength and corrosion resistance are paramount. The coarse UNRC thread and Class 2A fit enable rapid installation and reliable clamping in high-vibration settings, reducing assembly time and maintenance needs. With a 7/8" hex drive and standard socket head, it ensures easy access in confined spaces, while the partially threaded design allows for precise load-bearing adjustments. Ideal for securing structural components and industrial fixtures, this fastener delivers long-term reliability and compliance with ASTM A574 specifications, supporting efficient B2B procurement for demanding engineering projects.

Specification Summary & Compliance

This product adheres to precise dimensional standards, including a Class 2A thread fit for consistent engagement and a coarse 1 1/4"-7 UNRC thread with a minimum thread length of 3 1/8". Manufactured in compliance with ASTM A574 for material and mechanical properties, it also meets RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) regulations, ensuring environmental safety and suitability for industrial applications worldwide.