S-91257A859 3/4"-10 x 6" 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 and Grade 8 classification for reliable performance in high-stress applications
• Superior corrosion resistance through zinc yellow-chromate plating that protects against rust and extends service life in harsh environments
• Optimized thread engagement with UNC coarse threading and Class 2A fit ensuring secure fastening and vibration resistance
• Enhanced installation efficiency featuring external hex drive and 1 1/8" head width for easy torque application with standard tools
• Reduced material stress concentration through partial threading design that maintains shank strength while providing sufficient thread length
• Consistent hardness performance with Rockwell C33 rating that prevents deformation under heavy loads and repeated use
• Regulatory compliance assurance meeting multiple industry standards for quality, safety, and environmental responsibility

Professional Applications & Engineering Value

This Grade 8 hex head screw delivers critical engineering solutions for heavy-duty industrial applications where failure is not an option. The combination of 150,000 PSI tensile strength and Rockwell C33 hardness addresses common challenges in construction, machinery assembly, and structural frameworks where dynamic loads and vibration can compromise fastener integrity. The zinc yellow-chromate plating provides superior corrosion protection in demanding environments, while the UNC coarse thread pattern ensures rapid installation and reliable performance in various materials. The partial threading design maintains maximum shank strength while providing sufficient thread engagement, making these industrial screws ideal for applications requiring both clamping force and shear resistance. With its external hex drive and substantial head dimensions, this fastener enables efficient installation with standard tools, reducing assembly time while maintaining the highest performance standards.

Specification Summary & Compliance

This 3/4"-10 hex head screw features precise Class 2A thread fit tolerances with UNC coarse threading (10 threads per inch) and partial threading extending to a minimum of 1 3/4". Manufactured to exacting ASME B18.2.1 and SAE J429 specifications for dimensional accuracy and performance reliability. The fastener is fully compliant with RoHS 3 (2015/863/EU) restrictions on hazardous substances and REACH (EC 1907/2006) regulations concerning chemical safety, ensuring environmental responsibility and workplace safety compliance.