S-91247A779 9/16"-12 x 5 1/2" ASME B18.2.1, SAE J429 Medium-Strength Grade 5 Steel Hex Head Screws

Key Features & Benefits at a Glance

• Exceptional load-bearing capacity with 120,000 psi tensile strength, ideal for heavy-duty structural connections
• Superior corrosion resistance through zinc plating, extending service life in demanding environments
• Reliable mechanical performance with Rockwell C25 hardness, maintaining dimensional stability under stress
• Optimized coarse thread design (UNC) for faster installation and reduced cross-threading risks
• Precision Class 2A thread fit ensuring consistent engagement and vibration resistance
• External hex drive compatibility with standard tools for efficient assembly and maintenance
• Industry-standard compliance meeting ASME B18.2.1 and SAE J429 specifications for guaranteed interchangeability

Professional Applications & Engineering Value

This Grade 5 hex head screw delivers critical performance where structural integrity matters most. The zinc plated steel construction provides essential corrosion protection for outdoor equipment, machinery frames, and construction applications. Its 9/16"-12 UNC coarse thread design enables rapid assembly in steel-to-steel connections while the partial threading concentrates strength where needed. Engineers specify these external hex drive fasteners for their proven reliability in high-vibration environments, from industrial conveyor systems to heavy equipment manufacturing. The combination of 120,000 psi tensile strength and standardized dimensions ensures predictable performance across production runs and replacement scenarios.

Specification Summary & Compliance

Manufactured to Class 2A thread fit tolerances with UNC coarse threading (9/16"-12). Complies with ASME B18.2.1 and SAE J429 Grade 5 specifications. Meets environmental regulations including RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) compliance. Dimensions: 5 1/2" length, 13/16" head width, with minimum 1 3/8" thread length.