S-91571A434 7/8"-9 x 1 3/4" 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 certification and 120,000 psi tensile strength for reliable performance in critical applications
• Superior wear resistance due to Rockwell C19 hardness, ensuring long-term durability under repetitive loading
• Optimized installation efficiency through coarse UNC threading and external hex drive, enabling quick assembly with standard tools
• Maximum thread engagement with full threading along the 1 3/4" length, providing enhanced grip and vibration resistance
• Precise mechanical fit with Class 2A thread tolerance, minimizing play and maintaining alignment in assembled structures
• Broad regulatory compliance meeting ASME, ASTM, RoHS 3, and REACH standards for quality assurance and environmental safety
• Heavy-duty material construction using high-strength steel, capable of withstanding extreme industrial stresses

Professional Applications & Engineering Value

Engineered for high-stress structural connections, this Grade A325 hex head screw addresses common industrial challenges such as joint slippage, material fatigue, and environmental degradation. The 7/8"-9 UNC coarse thread design ensures rapid installation while maintaining excellent clamping force in steel frameworks, machinery bases, and construction assemblies. Its fully threaded configuration distributes load evenly across the entire shank, reducing stress concentration points that lead to failure. The external hex drive allows for high-torque application with common wrenches, making it ideal for maintenance and production environments where speed and reliability are paramount. Compatible with heavy-duty fastening systems, it provides a dependable solution for projects requiring consistent performance under dynamic loads.

Specification Summary & Compliance

This fastener maintains Class 2A thread fit per UNC standards, ensuring dimensional accuracy and interchangeability. Manufacturing adheres to ASME B18.2.6, ASTM A325, and ASTM F3125 specifications for structural bolts. Environmental compliance includes RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) regulations, confirming the absence of restricted substances. The combination of 120,000 psi tensile strength and Rockwell C19 hardness validates its suitability for demanding mechanical and construction applications.