S-91251A814 5/8"-11 x 5" ASTM A574 Alloy Steel Socket Head Screws

Key Features & Benefits at a Glance

• Exceptional tensile strength of 170,000 psi ensures reliable performance under extreme loads, minimizing the risk of fastener failure in critical applications.
• Superior corrosion resistance from the black-oxide finish protects against rust and degradation, extending service life in harsh industrial environments.
• Precise Class 3A thread fit guarantees tight, secure fastening with reduced risk of cross-threading, improving assembly efficiency and joint integrity.
• High hardness (Rockwell C37) provides excellent wear resistance, maintaining thread form and drive integrity through repeated use and high torque applications.
• 1/2" hex drive design allows for high torque application with standard tools, ensuring easy installation and removal even in confined spaces.
• Partially threaded shank offers optimal grip length for materials of varying thicknesses, providing versatile clamping force distribution.
• Compliance with ASTM A574, RoHS 3, and REACH ensures material consistency, environmental safety, and suitability for regulated industries.

Professional Applications & Engineering Value

Engineered for demanding environments, these black-oxide alloy steel socket head cap screws deliver robust performance where failure is not an option. The 5/8"-11 UNRC coarse thread and Class 3A thread fit provide superior engagement in metals and composites, resisting vibration loosening in machinery, automotive assemblies, and heavy equipment. The black-oxide surface treatment significantly enhances corrosion resistance without compromising dimensional accuracy, making these fasteners ideal for outdoor, marine, or chemically exposed settings. With a 5" length and partially threaded design, they accommodate thick-section materials and provide precise clamp load control, reducing stress concentration in structural joints. These screws are specified in applications requiring high-strength fasteners that meet rigorous industry standards for reliability and safety.

Specification Summary & Compliance

This socket head cap screw features a 5/8"-11 coarse thread with Class 3A thread fit per UNRC standards, ensuring precise dimensional tolerances for secure mating. Manufactured in compliance with ASTM A574 for material and mechanical properties, it also meets RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) environmental regulations, confirming suitability for global industrial use without hazardous substance restrictions.