S-91583A623 7/8"-9 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

• Superior corrosion resistance with hot-dipped galvanized steel coating, extending service life in harsh outdoor and industrial environments
• Exceptional structural integrity with 120,000 psi tensile strength and Rockwell C19 hardness for reliable heavy-duty load-bearing applications
• Optimized installation efficiency through coarse UNC threading and external hex drive, enabling faster assembly with standard tools
• Precise thread engagement with Class 2A thread fit and partial threading design, ensuring secure fastening without unnecessary thread interference
• Robust dimensional stability featuring 1-7/16" head width and 35/64" head height for superior wrench grip and torque transmission
• Regulatory compliance assurance meeting ASME, ASTM, RoHS 3 and REACH standards for quality and environmental responsibility
• Versatile grip length of 2-3/4" accommodates various material thicknesses in structural steel connections

Professional Applications & Engineering Value

These Grade A325 structural screws deliver critical performance where structural integrity cannot be compromised. The hot-dipped galvanized steel construction provides superior corrosion protection for long-term reliability in bridges, building frames, and industrial facilities exposed to weather elements. The coarse UNC threading ensures rapid installation in structural steel applications while maintaining vibration resistance. With partial threading and precise Class 2A thread fit, these hex head fasteners prevent thread galling and provide optimal clamp load distribution. The combination of 120,000 psi tensile strength and external hex drive makes them ideal for critical connections requiring high torque application and dependable performance under dynamic loads.

Specification Summary & Compliance

Manufactured to exacting standards with Class 2A thread fit tolerance and UNC coarse threading (7/8"-9). Complies with ASME B18.2.6, ASTM A325, and ASTM F3125 specifications for structural fasteners. Meets RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) compliance requirements. Dimensions include 4-1/4" length, 1-1/2" thread length, and 2-3/4" grip length in inch system measurements.