S-91257A844 3/4"-10 x 2 3/4" 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 demanding structural and heavy machinery applications.
• Superior corrosion resistance from zinc yellow-chromate plating, extending service life in harsh industrial environments.
• Reliable thread engagement with Class 2A fit and UNC coarse threading, ensuring secure fastening and vibration resistance.
• High-grade material performance through Grade 8 steel and Rockwell C33 hardness, providing excellent durability and wear resistance.
• Optimized for high-torque installation with a 1 1/8" external hex head, allowing for easy wrench access and secure tightening.
• Versatile partial threading design offering both strong grip in the threaded section and smooth shank for precise clamping control.
• Compliance with major industry standards including ASME B18.2.1 and SAE J429, ensuring consistent quality and interchangeability.

Professional Applications & Engineering Value

This Grade 8 hex head screw is engineered to solve critical fastening challenges in heavy-duty industrial settings. The 3/4"-10 UNC coarse thread with Class 2A fit provides excellent resistance to loosening under vibration, making it ideal for construction equipment, agricultural machinery, and structural steel connections. The zinc yellow-chromate plating delivers superior corrosion protection, significantly extending service life in outdoor or chemically aggressive environments. Its partially threaded design allows for precise clamp load distribution, preventing joint failure in high-stress applications. Manufactured from high-strength steel and meeting ASME B18.2.1 and SAE J429 specifications, this fastener ensures reliable performance where safety and durability are paramount.

Specification Summary & Compliance

This fastener features precision 3/4"-10 UNC coarse threading with Class 2A thread fit for consistent engagement. It complies with ASME B18.2.1 and SAE J429 manufacturing standards, ensuring dimensional accuracy and mechanical properties. The product is RoHS 3 (2015/863/EU) Compliant and REACH (EC 1907/2006) Compliant, meeting environmental and safety regulations for industrial use worldwide.