S-91251A696 9/16"-18 x 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 applications, reducing the risk of fastener failure.
• Superior corrosion resistance from the black-oxide finish prolongs service life in harsh or humid industrial environments.
• Precision Class 3A thread fit provides tight tolerances and secure mating, minimizing backlash and vibration loosening.
• Fine UNF thread spacing offers improved load distribution and better adjustment control compared to coarse threads.
• High hardness (Rockwell C37) enhances wear resistance, maintaining thread integrity through repeated assembly cycles.
• Hex socket drive design allows for high torque application and easy installation in confined spaces with standard tools.
• Full threading along the 3/4" length enables flexible positioning and consistent clamping force across the entire fastener.

Professional Applications & Engineering Value

This black-oxide alloy steel socket head cap screw is engineered for demanding applications where precision, strength, and environmental resistance are critical. The 9/16-18 UNF fine threads with Class 3A fit provide exceptional accuracy in machinery assembly, aerospace components, and heavy equipment manufacturing, reducing the need for rework. The black-oxide surface treatment offers a protective layer against oxidation and mild corrosion, extending service life without compromising the 170,000 psi tensile strength. Its hex drive design ensures reliable torque transmission, making it ideal for high-vibration environments such as automotive systems, industrial robots, and construction machinery where fastener integrity cannot be compromised.

Specification Summary & Compliance

This socket head cap screw features a 9/16-18 UNF thread with Class 3A precision fit and fine thread spacing, manufactured from high-strength alloy steel. It complies with ASTM A574 specification for socket head cap screws, ensuring consistent quality and performance. The product is fully RoHS 3 (2015/863/EU) Compliant and REACH (EC 1907/2006) Compliant, meeting international environmental and safety standards for industrial use.