S-90211A511 3/8"-24 x 1" SAE J429 Left-Hand Threaded High-Strength Steel Hex Head Screws

Key Features & Benefits at a Glance

• Exceptional load-bearing capability with 150,000 psi tensile strength and Rockwell C33 hardness for reliable performance in high-stress environments
• Superior corrosion protection through zinc yellow-chromate plating that extends service life in harsh industrial conditions
• Precise thread engagement with Class 3A fit and UNF fine threading ensuring vibration resistance and secure fastening
• Left-hand threading design providing specialized solutions for reverse-thread applications where standard fasteners would loosen
• Full threading coverage along the 1" length enables maximum grip strength and adjustment flexibility
• Heavy-duty Grade 8 classification meeting SAE J429 specifications for guaranteed quality and performance standards
• External hex drive compatibility with 9/16" head width for standard tooling and efficient installation

Professional Applications & Engineering Value

Engineered for demanding industrial applications, these Grade 8 hex head screws deliver critical performance where reverse rotation or high vibration environments threaten fastener integrity. The left-hand UNF fine threading with Class 3A fit provides exceptional resistance to loosening under counter-clockwise forces, making them ideal for rotating equipment, machinery with reverse torque requirements, and safety-critical assemblies. The zinc yellow-chromate plating creates a robust barrier against corrosion in outdoor, marine, or chemical-exposed settings, while the 150,000 psi tensile strength ensures structural integrity under extreme loads. These steel fasteners are particularly valuable in automotive, heavy equipment, and manufacturing applications where SAE J429 compliance and reliable external hex drive functionality are essential for maintenance and assembly efficiency.

Specification Summary & Compliance

This 3/8"-24 UNF left-hand thread screw features precise Class 3A thread fit tolerances with fine thread spacing, manufactured to SAE J429 specifications for Grade 8 fasteners. The inch system measurement ensures 1" length with 9/16" head width and 15/64" head height dimensions. The fully threaded design maintains consistent engagement, while the zinc yellow-chromate finish provides RoHS and REACH compliant corrosion protection for industrial applications requiring durable, high-strength fastening solutions.