S-91257A962 1"-8 x 4 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 through zinc yellow-chromate plating that protects against harsh industrial environments
• Optimized torque transmission with external hex drive design ensuring secure installation and removal
• Enhanced fatigue resistance from Rockwell C33 hardness maintaining structural integrity under repeated loading
• Reliable thread engagement with Class 2A thread fit providing consistent assembly performance
• Versatile installation flexibility through partial threading allowing for both clamping and alignment functions
• Industry-standard compliance meeting ASME B18.2.1 and SAE J429 specifications for quality assurance

Professional Applications & Engineering Value

Engineered for demanding industrial environments, these Grade 8 hex head screws deliver exceptional performance where failure is not an option. The 1"-8 UNC coarse thread configuration provides superior resistance to vibration loosening while enabling faster installation in structural steel, heavy machinery, and construction applications. The zinc yellow-chromate plating creates a protective barrier against corrosion, significantly extending service life in outdoor or chemically aggressive settings. With partial threading, these fasteners offer precise clamping force control while maintaining unthreaded shank strength. The combination of 150,000 PSI tensile strength and Rockwell C33 hardness ensures reliable performance in critical connections subjected to dynamic loads and extreme conditions, making them ideal for industrial machinery, structural frameworks, and heavy equipment assembly.

Specification Summary & Compliance

Manufactured to exacting standards with Class 2A thread fit tolerances ensuring consistent engagement and assembly reliability. These UNC coarse thread fasteners comply with ASME B18.2.1 dimensional specifications and SAE J429 material requirements for Grade 8 high-strength fasteners. The 1"-8 thread size with 4 1/4" length provides standardized compatibility across industrial applications. Manufacturing processes adhere to quality systems delivering precise external hex drive dimensions and partial threading configuration for optimal performance in heavy-duty fastening applications.