S-92620A598 5/16"-18 x 4 1/2" ASME B18.2.1, SAE J429 High-Strength Grade 8 Steel Hex Head Screws

Key Features & Benefits at a Glance

• Maximum Load-Bearing Capacity: Grade 8 classification and 150,000 psi tensile strength ensure reliable performance in high-stress applications, reducing the risk of fastener failure.
• Superior Corrosion Protection: Zinc yellow-chromate plating provides excellent resistance to rust and environmental degradation, extending service life in harsh conditions.
• High Durability & Wear Resistance: Rockwell C33 hardness offers exceptional resistance to deformation and wear, maintaining structural integrity under repeated loads.
• Easy Installation & Removal: External hex drive and standard UNC coarse threads allow for quick, secure fastening with common tools, saving time on assembly lines.
• Precision Thread Fit: Class 2A thread fit ensures consistent, reliable engagement with nuts and tapped holes, minimizing loosening from vibration.
• Full Thread Engagement: Fully threaded design maximizes grip strength across the entire length, ideal for applications requiring uniform clamping force.
• Industry Standard Compliance: Meets ASME B18.2.1 and SAE J429 specifications, guaranteeing interoperability and reliability in regulated industrial environments.

Professional Applications & Engineering Value

This Grade 8 hex head screw is engineered to address critical challenges in heavy-duty industrial and construction settings, where fastener failure can lead to costly downtime or safety hazards. The high-strength steel construction, combined with 150,000 psi tensile strength and Rockwell C33 hardness, ensures it withstands extreme mechanical stresses without stripping or shearing. The zinc yellow-chromate plating provides a robust barrier against corrosion, making it suitable for outdoor machinery, structural steel connections, and automotive assemblies exposed to moisture. With UNC coarse threads and Class 2A fit, it offers reliable, vibration-resistant fastening in equipment frames, truck chassis, and industrial machinery, reducing maintenance intervals and enhancing operational safety.

Specification Summary & Compliance

This fastener adheres to ASME B18.2.1 and SAE J429 standards, ensuring dimensional accuracy and performance reliability. Thread specifications include 5/16"-18 UNC coarse threads with a Class 2A fit for consistent engagement. The zinc yellow-chromate finish meets industry requirements for corrosion resistance, while the material and manufacturing process comply with relevant industrial regulations for heavy-duty applications.