S-91247A642 3/8"-16 x 4 1/2" ASME B18.2.1, SAE J429 Medium-Strength Grade 5 Steel Hex Head Screws

Key Features & Benefits at a Glance

• Exceptional load-bearing capacity with 120,000 psi tensile strength and Rockwell C25 hardness for reliable performance in demanding applications
• Superior corrosion resistance through zinc plating that protects against rust and extends service life in harsh environments
• Optimized torque transmission with external hex drive design providing secure tool engagement and preventing stripping during installation
• Enhanced vibration resistance through coarse UNC threading that maintains secure fastening under dynamic loads
• Precision manufacturing with Class 2A thread fit ensuring consistent performance and easy assembly in industrial settings
• Versatile partial threading allowing for both clamping force and adjustment flexibility in machinery and structural applications
• Regulatory compliance assurance meeting ASME B18.2.1, SAE J429 standards plus RoHS 3 and REACH environmental directives

Professional Applications & Engineering Value

This Grade 5 steel hex head screw delivers critical engineering solutions where high tensile strength and durability are paramount. The 3/8"-16 UNC coarse thread configuration provides excellent grip in metal-to-metal fastening applications, while the zinc plating surface treatment offers reliable corrosion protection for outdoor equipment, industrial machinery, and construction assemblies. The partially threaded design allows for precise clamping force distribution, making it ideal for securing heavy components where vibration resistance is crucial. With its external hex drive and substantial 4 1/2" length, this fastener enables efficient installation in confined spaces while maintaining the structural integrity required for load-bearing applications across manufacturing, automotive, and infrastructure sectors.

Specification Summary & Compliance

This hex head screw features precision Class 2A thread fit with 3/8"-16 UNC coarse threading and 1" minimum thread length. Manufactured to ASME B18.2.1 and SAE J429 Grade 5 specifications, it delivers consistent dimensional accuracy and mechanical properties. The fastener is fully compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) environmental regulations, ensuring safe use across global industrial markets while maintaining the high-performance standards required for critical assembly applications.