S-90211A346 1/2"-13 x 4" SAE J429 Left-Hand Threaded High-Strength 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 corrosion resistance through zinc yellow-chromate plating that extends service life in harsh environments
• Precise thread engagement with Class 3A fit and UNC coarse threading for secure fastening and vibration resistance
• Maximum torque transmission via external hex drive design that prevents tool slippage during installation
• Enhanced durability from Grade 8 steel construction with Rockwell C33 hardness for long-term reliability
• Full-length thread coverage ensuring even stress distribution across the entire 4" length
• Industry-standard compliance meeting SAE J429 specifications for quality assurance in industrial applications

Professional Applications & Engineering Value

This Grade 8 heavy-duty hex head screw delivers critical engineering solutions for demanding industrial environments where reverse-rotation forces are present. The left-hand UNC threading provides secure fastening in applications subject to counter-clockwise rotational forces, preventing accidental loosening in machinery, heavy equipment, and automotive systems. The zinc yellow-chromate plating creates a protective barrier against corrosion, significantly extending service life in outdoor or chemically aggressive settings. With fully threaded design and coarse thread spacing, this fastener ensures optimal load distribution across the entire 4" length, making it ideal for structural connections, machinery assembly, and equipment maintenance where vibration resistance and high tensile strength are paramount requirements.

Specification Summary & Compliance

Manufactured to precise dimensional standards with Class 3A thread fit and 1/2"-13 UNC coarse thread specifications. This left-hand threaded hex head screw features a 3/4" head width and 11/32" head height for standard tool compatibility. The fastener complies with SAE J429 specifications for Grade 8 requirements and meets industry standards for material composition and mechanical properties. The zinc yellow-chromate finish provides environmental protection while maintaining dimensional accuracy for reliable performance in industrial fastening applications.