S-91257A930 7/8"-9 x 9" 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 Rockwell C33 hardness, ideal for high-stress industrial applications
• Superior corrosion resistance provided by zinc yellow-chromate plating, extending service life in harsh environments
• Reliable fastening performance through Class 2A thread fit and 7/8"-9 UNC coarse threading, ensuring secure connections
• Optimized torque transmission with external hex drive and 1 5/16" head width for easy installation and removal
• Enhanced structural stability from Grade 8 steel construction and partial threading design
• Comprehensive regulatory compliance meeting ASME B18.2.1, SAE J429, RoHS 3, and REACH standards
• Versatile industrial application with 9" length and right-hand thread direction for diverse assembly requirements

Professional Applications & Engineering Value

This Grade 8 hex head screw delivers critical engineering solutions for heavy machinery, structural steel connections, and industrial equipment assembly. The 7/8"-9 UNC coarse threading combined with Class 2A thread fit provides superior vibration resistance and prevents loosening under dynamic loads. The zinc yellow-chromate plating creates a robust barrier against corrosion, significantly extending service life in demanding environments. With partial threading design and 150,000 psi tensile strength, this fastener maintains structural integrity where full thread engagement isn't required, reducing material stress concentrations. The external hex drive and substantial head dimensions ensure reliable torque application during installation, making it ideal for construction, mining equipment, and heavy vehicle manufacturing where failure isn't an option.

Specification Summary & Compliance

Manufactured to precise inch system dimensions with Class 2A thread fit tolerance and 7/8"-9 UNC coarse threading. Fully compliant with ASME B18.2.1 and SAE J429 specifications for dimensional accuracy and mechanical properties. Meets RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) environmental regulations, ensuring safe use across global markets. The Grade 8 classification guarantees consistent performance with Rockwell C33 hardness and 150,000 psi tensile strength verification.