S-91571A439 7/8"-9 x 5 1/2" 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 120,000 psi tensile strength and Grade A325 certification for reliable performance in demanding applications
• Superior wear resistance due to Rockwell C19 hardness, ensuring extended service life under heavy loads
• Optimized load distribution through 4" grip length and partial threading design for enhanced joint stability
• Precise installation compatibility with standard 1 7/16" external hex head for easy wrenching and torque control
• Consistent thread engagement with Class 2A UNC coarse threads providing reliable assembly in structural connections
• Comprehensive regulatory compliance meeting ASME B18.2.6, ASTM A325, RoHS 3 and REACH standards for global project acceptance
• Robust corrosion resistance from high-strength steel construction suitable for harsh industrial environments

Professional Applications & Engineering Value

This Grade A325 hex head screw delivers critical engineering solutions for structural steel connections, heavy machinery assembly, and construction applications where failure is not an option. The 7/8"-9 UNC coarse thread configuration ensures rapid installation while maintaining superior clamping force in structural steel members and built-up sections. The partially threaded design with 4" grip length concentrates thread engagement precisely where needed, preventing thread stripping in connection holes while optimizing load transfer. Manufactured from high-strength steel with Rockwell C19 hardness, these external hex head screws withstand vibration, dynamic loads, and extreme tension requirements in bridge construction, industrial framework, and heavy equipment manufacturing. The combination of 120,000 psi tensile strength and standardized dimensions per ASME B18.2.6 provides engineers with predictable performance for critical bolted joints.

Specification Summary & Compliance

This 5 1/2" length hex head screw features precise Class 2A thread fit with 7/8"-9 UNC coarse threads and partial threading configuration. Manufactured to ASME B18.2.6 dimensional standards and ASTM A325/ASTM F3125 material specifications. Fully compliant with RoHS 3 (2015/863/EU) restrictions on hazardous substances and REACH (EC 1907/2006) regulations for chemical safety. The fastener meets all mechanical properties for Grade A325 structural bolts including tensile strength, hardness, and material composition requirements.