S-91268A955 1 1/2"-6 x 4" ASME B18.2.1, SAE J429 High-Strength Grade 8 Steel Hex Head Screws

Key Features & Benefits at a Glance

• Exceptional load-bearing capacity with 150,000 psi tensile strength for reliable performance in high-stress applications
• Superior wear resistance thanks to Rockwell C33 hardness, ensuring extended service life in demanding environments
• Optimized thread engagement with UNC coarse threading and Class 2A fit for faster assembly and reduced cross-threading risks
• Heavy-duty construction meeting Grade 8 standards for critical applications requiring maximum fastener integrity
• Secure external hex drive with 2 1/4" head width for high-torque installation using standard tools
• Partial threading design providing both threaded and unthreaded sections for precise clamping control
• Regulatory compliance assurance with RoHS 3 and REACH standards for environmentally responsible manufacturing

Professional Applications & Engineering Value

This Grade 8 steel hex head screw delivers exceptional engineering value in heavy machinery, structural steel connections, and industrial equipment assembly. The 1 1/2"-6 UNC coarse thread configuration ensures rapid installation while maintaining superior holding power in thick materials and structural components. The external hex drive with substantial 2 1/4" head width accommodates high-torque applications without stripping, while the partial threading design prevents joint loosening under vibration. Manufactured to ASME B18.2.1 specifications, these industrial fasteners provide reliable performance in construction, mining equipment, and heavy vehicle applications where failure is not an option. The combination of 150,000 psi tensile strength and Rockwell C33 hardness ensures these screws withstand extreme mechanical stresses and environmental challenges.

Specification Summary & Compliance

This hex head screw features precise Class 2A thread fit tolerance for consistent engagement and meets ASME B18.2.1 dimensional requirements. The fastener conforms to SAE J429 Grade 8 strength specifications with verified mechanical properties. Regulatory compliance includes RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) standards, ensuring environmental responsibility. Critical dimensions include 1 1/2"-6 UNC coarse thread, 4" overall length with minimum 3 1/4" thread length, and inch system measurements throughout.