S-91251A003 7/16"-20 x 1 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 under high-stress conditions, reducing the risk of fastener failure.
• Superior corrosion resistance from the black-oxide finish on alloy steel, extending service life in demanding industrial environments.
• Precise Class 3A thread fit provides tighter tolerances for secure, vibration-resistant assemblies in critical applications.
• Fully threaded UNF fine thread design offers enhanced grip and load distribution compared to coarse threads.
• 3/8" hex drive socket head allows for high-torque installation with standard tools, minimizing stripping and improving efficiency.
• Rockwell C37 hardness balances durability with machinability, resisting wear while maintaining structural integrity.
• Compliance with ASTM A574, RoHS 3, and REACH ensures material consistency and environmental safety for global supply chains.

Professional Applications & Engineering Value

These socket head cap screws are engineered to address common industrial challenges such as vibration loosening and corrosion in heavy machinery, automotive, and aerospace assemblies. The black-oxide alloy steel construction provides a protective layer that reduces oxidation without compromising the high tensile strength, making them ideal for applications requiring repeated disassembly. The UNF fine threads and Class 3A fit ensure precise engagement in tapped holes, minimizing play and enhancing joint reliability. With a 3/8" hex drive, installers can apply sufficient torque for secure fastening without damaging the socket, streamlining maintenance and reducing downtime in production environments.

Specification Summary & Compliance

This screw adheres to inch system dimensions with a thread size of 7/16"-20 UNF and Class 3A thread fit for superior accuracy. It is manufactured in compliance with ASTM A574 specifications for alloy steel socket head cap screws, ensuring consistent mechanical properties. The product is fully compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) regulations, confirming the absence of restricted hazardous substances for safe use in industrial and export markets.