S-91247A926 1"-8 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 for reliable performance in demanding applications
• Superior corrosion resistance provided by zinc plating, extending service life in various industrial environments
• Optimized thread engagement through 1"-8 UNC coarse spacing and Class 2A thread fit for faster assembly and secure fastening
• Enhanced torque transmission via external hex drive and substantial 1 1/2" head width for efficient installation with standard tools
• Controlled partial threading (2 1/4" min thread length) on 5 1/2" shank for precise clamping force distribution
• Consistent mechanical properties ensured by Grade 5 classification and Rockwell C25 hardness for predictable performance
• Regulatory compliance assurance meeting ASME B18.2.1, RoHS 3, and REACH standards for quality and environmental safety

Professional Applications & Engineering Value

This Grade 5 hex head screw delivers critical engineering solutions for heavy-duty industrial applications where vibration resistance and structural integrity are paramount. The zinc plated steel construction provides essential corrosion protection in manufacturing facilities, construction sites, and machinery assembly. The 1"-8 UNC coarse thread design enables rapid installation in structural steel connections, equipment frames, and load-bearing assemblies, while the partially threaded configuration prevents thread damage in through-holes and maintains precise clamp load distribution. With 120,000 psi tensile strength and external hex drive, these fasteners withstand extreme mechanical stresses while allowing high-torque installation using standard hex wrenches - making them ideal for critical joints in construction equipment, industrial machinery, and transportation infrastructure where failure is not an option.

Specification Summary & Compliance

This hex head screw features precise Class 2A thread fit tolerances with 1"-8 UNC coarse thread spacing and partial threading (minimum 2 1/4" thread length) on a 5 1/2" overall length. Manufactured to ASME B18.2.1 specifications where applicable per SAE J429 Grade 5 requirements, with material hardness of Rockwell C25 and tensile strength of 120,000 psi. The product is fully compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) environmental regulations, ensuring safe use across industrial sectors.