S-91251A697 9/16"-18 x 1" ASTM A574 Alloy Steel Socket Head Screws

Key Features & Benefits at a Glance

• Exceptional tensile strength of 170,000 psi ensures reliable performance under high-stress conditions, reducing the risk of fastener failure in demanding applications.
• Superior corrosion resistance from the black-oxide finish protects against rust and degradation, extending service life in harsh industrial environments.
• Precision Class 3A thread fit guarantees tight tolerances and secure fastening, minimizing backlash and improving assembly accuracy.
• High hardness (Rockwell C37) provides excellent wear resistance, maintaining thread integrity and drive performance through repeated use.
• Fine UNF threads offer improved load distribution and vibration resistance compared to coarse threads, ideal for precision mechanical assemblies.
• Fully threaded design allows for maximum adjustability and holding power along the entire length, accommodating various material thicknesses.
• Hex socket drive (7/16") enables high-torque installation with standard tools, reducing slippage and ensuring efficient, secure tightening.

Professional Applications & Engineering Value

Engineered for high-strength fastening in critical industrial and mechanical systems, this black-oxide alloy steel socket head cap screw addresses common challenges like vibration loosening, corrosion, and tensile overload. The Class 3A UNF fine thread ensures precise engagement in tapped holes, reducing the risk of cross-threading and providing superior clamp load retention in dynamic environments. Its fully threaded rod type and hex drive design facilitate easy installation in confined spaces, making it ideal for machinery, automotive components, and heavy equipment where reliability and corrosion resistance are paramount. The combination of 170,000 psi tensile strength and Rockwell C37 hardness ensures durability under cyclic loading, offering long-term performance in precision fasteners applications.

Specification Summary & Compliance

This socket head cap screw features a 9/16"-18 UNF fine thread with Class 3A fit for high-precision assembly, ensuring tight dimensional accuracy per inch-based standards. It is manufactured in compliance with ASTM A574 for alloy steel socket head cap screws, guaranteeing consistent material and mechanical properties. The product is fully RoHS 3 (2015/863/EU) Compliant and REACH (EC 1907/2006) Compliant, meeting environmental and safety regulations for restricted substances, making it suitable for global industrial use.