S-91571A446 1"-8 x 3 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

• Exceptional structural integrity with Grade A325 classification and 120,000 psi tensile strength for reliable performance in demanding applications
• Superior durability and wear resistance thanks to Rockwell C19 hardness steel construction that withstands heavy loads and harsh conditions
• Optimized load distribution through partially threaded design with 1½" grip length for secure connections in structural assemblies
• Quick installation and removal with external hex drive and 1⅝" head width providing excellent tool engagement and torque transmission
• Reliable thread engagement with Class 2A fit UNC coarse threading that resists vibration loosening and ensures consistent clamping force
• Industry-standard compatibility meeting ASME B18.2.6, ASTM A325, and ASTM F3125 specifications for guaranteed interchangeability
• Environmental compliance assurance with RoHS 3 and REACH regulations for sustainable procurement in regulated industries

Professional Applications & Engineering Value

These Grade A325 hex head screws deliver critical engineering value in structural steel connections, bridge construction, and heavy machinery assembly where failure is not an option. The heavy-duty steel construction with Rockwell C19 hardness provides exceptional resistance to shear and tensile stresses, while the 1"-8 UNC coarse threading ensures rapid installation without cross-threading in field conditions. The partially threaded design concentrates strength where needed most, preventing thread damage during installation and maintaining 120,000 psi tensile strength across the shank. These structural hex bolts solve common industrial challenges including vibration-induced loosening, corrosion concerns, and compliance requirements for critical infrastructure projects.

Specification Summary & Compliance

This heavy-duty steel fastener features precise Class 2A thread fit with 1"-8 UNC coarse threading and 3¼" overall length. Manufactured to exacting ASME B18.2.6 dimensional standards with material properties conforming to ASTM A325 and ASTM F3125 specifications. Fully compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) environmental regulations, ensuring suitability for global industrial applications with strict chemical substance restrictions.