S-91257A175 5/8"-11 x 10 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 with 150,000 psi tensile strength ensures reliable performance in high-stress industrial environments
• Superior Corrosion Protection - Zinc yellow-chromate plating provides excellent resistance against rust and environmental degradation
• Optimized Thread Engagement - Coarse UNC threading with Class 2A fit guarantees secure fastening and easier installation in tough materials
• Enhanced Durability - Rockwell C33 hardness maintains structural integrity under repeated stress and vibration
• Industry-Standard Compliance - Meets ASME B18.2.1 and SAE J429 specifications for consistent quality and interchangeability
• Versatile Partial Threading - 1 3/4" minimum thread length allows for precise clamping force control in various material thicknesses
• Secure External Hex Drive - 15/16" head width provides superior torque transmission and prevents tool slippage during installation

Professional Applications & Engineering Value

Engineered for heavy-duty industrial applications, these Grade 8 hex head screws deliver exceptional performance where failure is not an option. The 5/8"-11 UNC coarse threading with Class 2A fit ensures reliable engagement in structural steel, heavy machinery, and construction equipment, reducing the risk of cross-threading in field installations. The zinc yellow-chromate plating provides critical corrosion resistance in demanding environments, from manufacturing facilities to outdoor infrastructure. With 150,000 psi tensile strength and Rockwell C33 hardness, these partially threaded screws maintain clamping force under extreme vibration and dynamic loads, making them ideal for critical connections in construction, automotive, and industrial machinery where safety and reliability are paramount.

Specification Summary & Compliance

This 10 1/2" hex head screw features precise Class 2A thread fit with 5/8"-11 UNC coarse threading and external hex drive configuration. Manufactured to meet ASME B18.2.1 and SAE J429 specifications, ensuring dimensional accuracy and mechanical properties compliance. The zinc yellow-chromate finish provides superior corrosion protection while maintaining Grade 8 strength requirements with verified 150,000 psi tensile strength and Rockwell C33 hardness.