S-91251A813 5/8"-11 x 4 3/4" 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 and heavy-duty applications, reducing the risk of fastener failure.
• Superior corrosion resistance from the black-oxide finish on alloy steel extends service life in harsh industrial environments, minimizing maintenance needs.
• Precise Class 3A thread fit provides tighter tolerances for secure, vibration-resistant assemblies, enhancing joint integrity.
• Coarse UNC threads enable quicker installation and better performance in materials prone to stripping or where rapid assembly is critical.
• High hardness (Rockwell C37) offers excellent wear resistance, maintaining thread form and drive integrity over repeated use.
• 1/2" hex drive socket head allows for high torque application with standard tools, facilitating easy installation and removal in confined spaces.
• Partially threaded design provides unthreaded shank for precise clamping and alignment in machinery and structural applications.

Professional Applications & Engineering Value

This Black-Oxide Alloy Steel Socket Head Cap Screw is engineered to address critical challenges in demanding industrial settings, such as machinery assembly, automotive systems, and heavy equipment manufacturing. The combination of high tensile strength (170,000 psi) and Rockwell C37 hardness ensures durability under dynamic loads and vibrations, preventing loosening and fatigue failures. The black-oxide surface treatment provides a protective layer against rust and corrosion, making it suitable for outdoor or humid environments. With coarse 5/8"-11 UNC threads and a Class 3A thread fit, it offers superior engagement and resistance to stripping in soft metals or composite materials, streamlining installation while maintaining long-term reliability. Ideal for applications requiring robust fastening performance and compliance with industry standards, this screw delivers consistent value in construction, aerospace, and manufacturing sectors.

Specification Summary & Compliance

This socket head cap screw adheres to precise dimensional standards, including Class 3A thread fit for tight tolerances and UNC coarse threads with a size of 5/8"-11. It meets ASTM A574 specifications for high-strength alloy steel fasteners, ensuring consistent quality and performance. The product is fully compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) regulations, confirming its safety for use in restricted substance-sensitive applications. Manufactured with a right-hand thread direction and partially threaded design, it supports reliable fastening in various industrial assemblies.