S-91571A418 5/8"-11 x 4 1/4" ASME B18.2.6, ASTM A325, ASTM F3125 Medium-Strength Steel Heavy Hex Head Screws for Structural Applications

Key Features & Benefits at a Glance

• Exceptional structural integrity with Grade A325 classification and 120,000 psi tensile strength for reliable performance in demanding applications
• Superior corrosion resistance and durability through high-grade steel construction with Rockwell C19 hardness rating
• Optimized load distribution with 3" grip length and partial threading design for enhanced joint stability
• Precise installation and removal enabled by external hex drive and 1 1/16" head width for secure tool engagement
• Industry-standard compatibility with UNC coarse thread pattern and Class 2A thread fit ensuring proper mating with standard nuts
• Regulatory compliance assurance meeting ASME B18.2.6, ASTM A325, and ASTM F3125 specifications for quality verification
• Environmental responsibility through RoHS 3 and REACH compliance for sustainable procurement

Professional Applications & Engineering Value

These Grade A325 hex head screws deliver critical engineering solutions for structural connections where vibration resistance and tensile loading are primary concerns. The partially threaded design with 3" grip length ensures that the unthreaded shank bears against connected materials, preventing loosening under dynamic loads while the UNC coarse thread provides rapid installation in steel-to-steel applications. The external hex drive configuration offers superior torque transmission during installation, making these heavy-duty fasteners ideal for structural steel construction, bridge building, and industrial machinery assembly. With 120,000 psi tensile strength and verified compliance with ASME B18.2.6 standards, these screws provide engineers with reliable performance data for critical connection calculations.

Specification Summary & Compliance

This 5/8"-11 hex head screw features precise Class 2A thread fit tolerances and UNC coarse threading with 1 1/4" thread length. Manufacturing adheres to ASME B18.2.6 dimensional specifications and ASTM A325/ASTM F3125 material and mechanical property requirements. The product is fully compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) environmental regulations, ensuring responsible material sourcing and manufacturing processes for global industrial applications.