S-91257A772 9/16"-12 x 3 3/4" ASME B18.2.1, SAE J429 High-Strength Grade 8 Steel Hex Head Screws

Key Features & Benefits at a Glance

• Maximum Load-Bearing Capacity - Grade 8 classification with 150,000 psi tensile strength ensures reliable performance in high-stress industrial applications
• Superior Corrosion Protection - Zinc yellow-chromate plating provides enhanced resistance to rust and environmental degradation
• Optimized Fastening Efficiency - Partial threading design allows for precise tension control and reduced installation time
• Exceptional Durability - Rockwell C33 hardness rating maintains structural integrity under repeated stress and vibration
• Secure Drive Engagement - External hex head design enables high-torque application with standard tools
• Precision Thread Compatibility - Class 2A UNC coarse threads ensure consistent engagement and reliable fastening
• Industry Compliance Assurance - Meets critical standards for quality and environmental regulations

Professional Applications & Engineering Value

These Grade 8 hex head screws deliver exceptional engineering value in demanding industrial environments where failure is not an option. The steel construction combined with 150,000 psi tensile strength makes them ideal for heavy machinery, structural frameworks, and equipment requiring high-strength fasteners. The zinc yellow-chromate plating provides superior corrosion resistance, extending service life in harsh conditions while maintaining electrical conductivity. The partial threading design allows for precise clamp load distribution, preventing joint relaxation in vibrating applications. These 9/16"-12 UNC coarse thread fasteners are particularly valuable in construction, automotive, and manufacturing sectors where external hex drive accessibility and high torque requirements are critical.

Specification Summary & Compliance

This 3 3/4" length hex head screw features precision Class 2A thread fit with UNC coarse threading (9/16"-12) ensuring reliable engagement and installation consistency. Manufactured to exacting ASME B18.2.1 and SAE J429 specifications, these fasteners maintain dimensional accuracy and performance reliability. The product is fully compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) environmental regulations, meeting the latest industry standards for hazardous substance restrictions and chemical safety.