S-91251A815 5/8"-11 x 5 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 under extreme loads, reducing the risk of fastener failure in critical applications.
• Superior corrosion resistance from the black-oxide coating extends service life in harsh industrial environments, minimizing maintenance and replacement costs.
• Precision Class 3A thread fit provides tighter tolerances for secure, vibration-resistant assemblies, enhancing joint integrity.
• High hardness (Rockwell C37) offers excellent wear resistance, maintaining thread form and drive integrity through repeated use.
• Coarse UNC threads enable faster installation and better performance in materials prone to galling or where quick assembly is required.
• 1/2" hex drive design allows for high torque application with standard tools, ensuring efficient installation and removal.
• Compliance with ASTM A574, RoHS 3, and REACH guarantees material consistency and environmental safety, meeting stringent industry and regulatory standards.

Professional Applications & Engineering Value

These black-oxide alloy steel socket head cap screws are engineered to address common industrial challenges such as vibration loosening, corrosion-induced degradation, and high-stress fatigue. The partially threaded design with 5/8"-11 UNC coarse threads ensures optimal grip in ductile materials, while the Class 3A thread fit minimizes backlash in precision machinery. Ideal for heavy-duty applications like machinery frames, automotive assemblies, and construction equipment, these screws provide reliable fastening where high tensile strength and corrosion resistance are critical. The 1/2" hex drive facilitates secure tool engagement, reducing slippage during high-torque installations in confined spaces.

Specification Summary & Compliance

This socket head cap screw features a 5/8"-11 UNC coarse thread with Class 3A fit for precise engagement, and a length of 5 1/4" with a minimum thread length of 1 3/4". Manufactured to ASTM A574 specifications, it ensures consistent mechanical properties. The product is compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) environmental regulations, supporting sustainable and safe industrial practices.