S-91257A867 3/4"-16 x 3 1/4" 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 provided by zinc yellow-chromate plating, extending service life in demanding environments
• Precise thread engagement with UNF fine thread and Class 2A fit ensuring secure, vibration-resistant connections
• Optimized torque transmission through the external hex drive and 1 1/8" head width for easy installation and removal
• Enhanced durability with Rockwell C33 hardness maintaining structural integrity under repeated stress
• Versatile partial threading allowing for both clamping and alignment functions in various assembly scenarios
• Regulatory compliance assurance meeting industry standards for quality and environmental safety

Professional Applications & Engineering Value

This Grade 8 hex head screw delivers exceptional engineering value through its high-strength steel construction and zinc yellow-chromate plating, specifically designed to address critical industrial challenges. The 3/4"-16 UNF fine thread configuration provides superior resistance to vibration loosening in heavy machinery, construction equipment, and automotive assemblies where reliable fastening is paramount. The partial threading design allows for optimal stress distribution while maintaining alignment precision in structural applications. With 150,000 psi tensile strength and Rockwell C33 hardness, this fastener withstands extreme mechanical stresses while the corrosion-resistant finish ensures long-term performance in harsh operating environments. These industrial fasteners are engineered to prevent joint failure and reduce maintenance frequency in critical applications.

Specification Summary & Compliance

This high-performance fastener features precise Class 2A thread fit with 3/4"-16 UNF fine thread specifications and partial threading extending to a minimum of 1 3/4". Manufactured in compliance with ASME B18.2.1 and SAE J429 Grade 8 standards, ensuring dimensional accuracy and mechanical properties. The product is fully compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) environmental regulations, meeting the latest industry requirements for hazardous substance restrictions.