S-91268A319 3/8"-16 x 4 1/2" ASME B18.2.1, SAE J429 High-Strength Grade 8 Steel Hex Head Screws

Key Features & Benefits at a Glance

• Exceptional load-bearing capacity with 150,000 PSI tensile strength for reliable performance in high-stress applications
• Superior corrosion resistance and durability thanks to Grade 8 steel construction and Rockwell C33 hardness
• Secure and efficient installation with external hex drive design providing maximum torque transfer
• Optimized thread engagement through UNC coarse threading and Class 2A fit for faster assembly and vibration resistance
• Versatile partial threading allowing for both clamping and alignment functions in various industrial setups
• Right-hand thread direction ensuring standard compatibility and straightforward installation procedures
• Comprehensive regulatory compliance meeting ASME B18.2.1, SAE J429 standards plus RoHS 3 and REACH environmental directives

Professional Applications & Engineering Value

This Grade 8 steel hex head screw delivers exceptional engineering value for heavy machinery, structural steel connections, and industrial equipment assembly. The 3/8"-16 UNC coarse threads provide superior resistance to vibration loosening while enabling rapid installation in demanding environments. With 150,000 PSI tensile strength and Rockwell C33 hardness, this fastener maintains integrity under extreme loads and repetitive stress cycles. The partially threaded design allows the unthreaded shank to function as a precision pilot in alignment-critical applications, while the external hex drive accommodates high-torque installation tools without stripping. These industrial hex screws solve critical challenges in construction, automotive, and manufacturing sectors where failure prevention and long-term reliability are paramount.

Specification Summary & Compliance

This 4 1/2" length hex head screw features precise 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 8 specifications, ensuring dimensional accuracy and mechanical performance. The fastener is fully compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) environmental regulations, making it suitable for global industrial applications requiring strict material composition controls.