S-92620A570 1/4"-28 x 3 1/2" ASME B18.2.1, SAE J429 High-Strength Grade 8 Steel Hex Head Screws

Key Features & Benefits at a Glance

• Exceptional load-bearing capability with 150,000 PSI tensile strength for critical structural applications
• Superior corrosion resistance through zinc yellow-chromate plating that withstands harsh industrial environments
• Precise thread engagement with Class 2A UNF fine threads ensuring reliable, vibration-resistant connections
• Maximum thread contact through full threading along the entire 3½" length for enhanced grip strength
• Optimized installation efficiency with external hex drive design allowing high-torque application
• Grade 8 reliability meeting ASME B18.2.1 and SAE J429 specifications for quality assurance
• Rockwell C33 hardness providing excellent wear resistance and durability under repeated stress

Professional Applications & Engineering Value

These Grade 8 hex head screws deliver critical performance in demanding industrial environments where failure is not an option. The UNF fine thread configuration provides superior resistance to vibration loosening compared to coarse threads, making them ideal for machinery, automotive assemblies, and structural frameworks subject to dynamic loads. The zinc yellow-chromate plating creates a protective barrier against corrosion while maintaining electrical conductivity, essential for grounding applications. With fully threaded design and external hex drive, these fasteners enable complete penetration through thick materials and permit high-torque installation without stripping. The combination of 150,000 PSI tensile strength and Rockwell C33 hardness ensures these screws maintain clamp force under extreme conditions, preventing joint failure in heavy equipment, construction machinery, and industrial manufacturing applications.

Specification Summary & Compliance

Manufactured to exacting Class 2A thread fit tolerances for consistent engagement and proper clearance. Complies with ASME B18.2.1 dimensional standards and SAE J429 material specifications for Grade 8 fasteners. Features 1/4"-28 UNF fine threads with right-hand direction and 3½" fully threaded length. The zinc yellow-chromate plating provides corrosion protection while the external hex drive with 7/16" head width accommodates standard wrenching tools. Meets industry standards for heavy-duty mechanical applications requiring verified performance metrics.