S-91251A877 7/8"-9 x 1 1/4" 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.
• Class 3A thread fit provides superior precision and tighter tolerances for secure, vibration-resistant assemblies in demanding environments.
• Black-oxide coating on alloy steel enhances corrosion resistance and durability, extending service life in harsh operating conditions.
• Fully threaded design allows for maximum grip and adjustability across the entire length, simplifying installation in various material thicknesses.
• Hex socket drive enables high-torque application with standard tools, minimizing stripping and improving assembly efficiency.
• Rockwell C37 hardness offers excellent wear resistance, maintaining thread integrity and performance under repetitive loads.
• Compliance with ASTM A574, RoHS 3, and REACH ensures adherence to industry standards and environmental regulations for safe, global use.

Professional Applications & Engineering Value

This 7/8"-9 UNC Socket Head Cap Screw is engineered from black-oxide alloy steel to address critical challenges in heavy machinery, automotive, and construction sectors. The coarse thread and Class 3A fit provide superior clamping force and vibration resistance, preventing loosening in dynamic loads. With a fully threaded rod and hex drive, it simplifies alignment and installation in confined spaces, reducing assembly time. The high tensile strength and hardness ensure longevity in structural applications, while the black-oxide surface treatment combats rust, making it ideal for outdoor or corrosive environments. This screw delivers reliable industrial fastening solutions that enhance equipment safety and operational efficiency.

Specification Summary & Compliance

This socket head cap screw features a 7/8"-9 UNC coarse thread with Class 3A precision fit, ensuring tight tolerances per inch-system standards. It is manufactured in compliance with ASTM A574 specifications for high-strength alloy steel fasteners. The product meets RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) regulatory requirements, confirming its suitability for environmentally conscious and global industrial use.