S-91257A866 3/4"-10 x 10" 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 for reliable performance in high-stress applications
• Superior corrosion resistance provided by zinc yellow-chromate plating, extending service life in demanding industrial environments
• Optimized torque transmission through the external hex drive and 1 1/8" head width for secure installation and removal
• Enhanced vibration resistance with coarse UNC threading that maintains grip under dynamic loading conditions
• Precise thread engagement ensured by Class 2A thread fit for consistent assembly quality and reduced cross-threading risk
• Versatile partial threading design allowing for both clamping and alignment functions in structural applications
• Regulatory compliance assurance meeting ASME B18.2.1, SAE J429, RoHS 3, and REACH standards for quality and environmental safety

Professional Applications & Engineering Value

These Grade 8 hex head screws deliver critical engineering solutions for heavy machinery, structural steel connections, and industrial equipment assembly. The 3/4"-10 UNC coarse thread configuration provides excellent engagement in both metallic and composite materials, while the zinc yellow-chromate plating creates a durable barrier against corrosion in outdoor or chemically aggressive environments. The partially threaded design offers precise clamping control where unthreaded shank sections bear against components, preventing loosening under vibration. With 150,000 psi tensile strength and Rockwell C33 hardness, these fasteners maintain structural integrity in high-load applications such as construction equipment, transportation systems, and manufacturing infrastructure, ensuring long-term reliability where failure is not an option.

Specification Summary & Compliance

Manufactured to exacting dimensional standards with Class 2A thread fit tolerances for consistent performance. The 3/4"-10 UNC coarse thread specification ensures compatibility with standard components and tooling. These hex head screws conform to ASME B18.2.1 and SAE J429 mechanical specifications, guaranteeing dimensional accuracy and mechanical properties. Environmental compliance is verified through RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) certifications, ensuring responsible material usage and workplace safety standards.