S-91251A653 3/8"-16 x 7 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 high-stress conditions, reducing failure risks in demanding applications.
• Corrosion-resistant black-oxide finish on alloy steel enhances durability and provides protection against rust in harsh industrial environments.
• Precise Class 3A thread fit guarantees tight, secure fastening with minimal backlash, ideal for precision assemblies.
• Hex socket drive design with 5/16" drive size allows for easy installation in confined spaces using standard tools.
• Partially threaded shank enables controlled clamping force and prevents thread damage during repeated adjustments.
• Coarse UNC threads facilitate quick assembly and disassembly, saving time in maintenance and production cycles.
• Compliance with ASTM A574 and environmental standards (RoHS 3, REACH) ensures consistent quality and safe use in regulated industries.

Professional Applications & Engineering Value

This black-oxide alloy steel socket head cap screw is engineered to address common industrial challenges such as vibration loosening and corrosion in machinery, automotive, and heavy equipment applications. The 3/8"-16 UNC coarse thread design provides excellent grip in metals and plastics, while the partially threaded configuration concentrates stress efficiently to prevent joint failure. With a Rockwell C37 hardness and robust hex drive, it withstands high torque during installation, making it suitable for critical assemblies where reliability and repeatability are paramount. Its inch system measurements ensure compatibility with North American equipment standards, reducing integration issues.

Specification Summary & Compliance

This fastener adheres to Class 3A thread fit tolerances for superior precision and meets ASTM A574 specifications for high-strength socket head cap screws. It is fully compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) regulations, ensuring environmental safety. Dimensions include a 7 1/4" length, 3/8"-16 UNC coarse threads, and a 5/16" hex drive, manufactured from alloy steel with a black-oxide surface treatment for enhanced performance.