S-91257A639 3/8"-16 x 3 3/4" ASME B18.2.1, SAE J429 High-Strength Grade 8 Steel Hex Head Screws

Key Features & Benefits at a Glance

• Maximum load-bearing capacity with 150,000 psi tensile strength for critical structural applications
• Superior corrosion resistance through zinc yellow-chromate plating in harsh industrial environments
• Precise thread engagement with Class 2A UNC coarse threads ensuring reliable fastening
• Exceptional durability backed by Rockwell C33 hardness and Grade 8 certification
• Optimized torque transmission through external hex drive design for secure installation
• Reduced weight without compromising strength through partial threading design
• Full regulatory compliance meeting ASME, SAE, RoHS 3 and REACH standards

Professional Applications & Engineering Value

These Grade 8 hex head screws deliver exceptional performance in demanding industrial applications where failure is not an option. The 3/8"-16 UNC coarse thread configuration provides superior resistance to vibration loosening while enabling rapid assembly in heavy machinery, structural steel frameworks, and automotive systems. The zinc yellow-chromate plating creates a protective barrier against corrosion in outdoor or chemically aggressive environments, significantly extending service life. With partial threading optimizing the strength-to-weight ratio, these high-tensile steel fasteners are engineered to maintain structural integrity under extreme loads while meeting rigorous industry standards for quality and safety.

Specification Summary & Compliance

This 3/8"-16 UNC hex head screw features precise Class 2A thread fit with 3 3/4" length and 1" minimum thread length. Manufactured to ASME B18.2.1 and SAE J429 Grade 8 specifications, ensuring dimensional accuracy and mechanical properties. Fully compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) environmental regulations, making them suitable for global industrial applications requiring strict chemical substance control.