S-91257A868 3/4"-10 x 12" ASME B18.2.1, SAE J429 High-Strength Grade 8 Steel Hex Head Screws

Key Features & Benefits at a Glance

• Exceptional tensile strength of 150,000 psi ensures reliable performance in high-stress applications, reducing the risk of fastener failure.
• Superior corrosion resistance from zinc yellow-chromate plating extends service life in harsh industrial environments, minimizing maintenance needs.
• High hardness (Rockwell C33) provides excellent wear resistance, maintaining thread integrity and drive engagement over repeated use.
• Coarse UNC threading with Class 2A fit offers quick assembly and secure fastening, ideal for vibration-prone settings.
• Partially threaded design allows for precise clamping force distribution, preventing joint loosening in heavy machinery.
• External hex drive and standard head dimensions enable easy installation with common tools, speeding up assembly processes.
• Compliance with ASME, SAE, RoHS, and REACH guarantees quality and environmental safety, meeting global industrial standards.

Professional Applications & Engineering Value

This Grade 8 hex head screw is engineered to address critical challenges in heavy-duty industrial applications, such as construction equipment, automotive assemblies, and machinery frames. Its steel construction and high tensile strength of 150,000 psi provide robust resistance to dynamic loads and vibrations, reducing downtime from fastener fatigue. The zinc yellow-chromate plating delivers superior corrosion protection, essential for outdoor or chemically exposed environments, while the coarse UNC thread ensures rapid installation and reliable grip in coarse-grained materials. With a partial thread design, it optimizes clamping force on specific joint sections, enhancing structural integrity. These features make it a dependable choice for engineers seeking durable, compliant fasteners that uphold safety and performance in demanding settings.

Specification Summary & Compliance

This screw adheres to precise dimensional standards, including a Class 2A thread fit for consistent engagement and UNC coarse threading with a size of 3/4"-10. It meets ASME B18.2.1 and SAE J429 specifications for mechanical properties and is fully compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) regulations, ensuring environmental safety and material reliability.