S-91251A701 9/16"-18 x 2 1/2" 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.
• Precise Class 3A thread fit provides superior engagement and vibration resistance, maintaining joint integrity in demanding environments.
• Black-oxide finish on alloy steel offers enhanced corrosion resistance, extending service life in various industrial conditions.
• Fine UNF thread design allows for finer adjustments and improved clamping force control compared to coarse threads.
• Hex socket drive (7/16") enables high-torque installation with standard tools, minimizing stripping and ensuring secure fastening.
• Full threading along the 2-1/2" length provides consistent holding power and flexibility in assembly positioning.
• Compliance with ASTM A574, RoHS 3, and REACH guarantees material quality and environmental safety for global supply chain integration.

Professional Applications & Engineering Value

This Black-Oxide Alloy Steel Socket Head Cap Screw is engineered to address critical challenges in heavy machinery, automotive, and aerospace assemblies where vibration loosening and high tensile loads are common. The 9/16"-18 UNF fine thread and Class 3A fit ensure minimal backlash and superior fatigue resistance, preventing joint failure under dynamic stresses. The hex drive socket head design allows for compact installation in confined spaces, while the 170,000 PSI tensile strength and Rockwell C37 hardness provide durability against shear and impact forces. Ideal for precision equipment and structural frameworks, this fastener delivers long-term reliability and reduces maintenance downtime in industrial settings.

Specification Summary & Compliance

This socket head cap screw features a 9/16"-18 UNF fine thread with Class 3A precision tolerance for accurate fitment. It is manufactured in accordance with ASTM A574 specifications, ensuring consistent material and mechanical properties. The product is fully compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) regulations, confirming its suitability for use in environmentally regulated markets and applications requiring strict adherence to health and safety standards.