S-91251A316 7/8"-14 x 7" 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.
• Black-oxide finish on alloy steel provides corrosion resistance and a durable, non-reflective surface suitable for harsh environments.
• Class 3A thread fit offers precise, tight-tolerance threading for secure, vibration-resistant connections in critical assemblies.
• Partially threaded design with 2 1/4" minimum thread length allows for optimal clamping force and easier alignment in varied material thicknesses.
• 3/4" hex drive and standard socket head enable high-torque installation with common tools, improving assembly efficiency and reducing strip-out.
• Fine UNRF thread spacing enhances grip and load distribution, ideal for applications requiring fine adjustment and stability.
• Rockwell C37 hardness balances toughness and machinability, resisting wear and deformation under heavy loads.

Professional Applications & Engineering Value

This Black-Oxide Alloy Steel Socket Head Cap Screw is engineered to address demanding industrial challenges where strength, precision, and environmental compliance are critical. The 7/8"-14 UNRF fine threads and Class 3A fit provide superior vibration resistance and sealing in machinery, automotive, and heavy equipment assemblies, minimizing loosening and maintenance needs. The partially threaded rod type ensures effective clamping across joint variations, while the black-oxide surface treatment extends service life in corrosive or high-humidity settings. Ideal for high-strength bolting in construction, aerospace, and manufacturing, this fastener delivers reliable performance under extreme mechanical stress, supported by its 170,000 psi tensile strength and robust material properties.

Specification Summary & Compliance

This socket head cap screw features precise 7/8"-14 UNRF fine threads with Class 3A thread fit for tight tolerances and consistent engagement. It complies with ASTM A574 specifications for high-strength alloy steel fasteners, ensuring material integrity and manufacturing consistency. The product is also RoHS 3 (2015/863/EU) Compliant and REACH (EC 1907/2006) Compliant, meeting environmental and safety standards for restricted substances, making it suitable for global industrial use.