S-92620A592 5/8"-18 x 2 1/4" ASME B18.2.1, SAE J429 High-Strength Grade 8 Steel Hex Head Screws

Key Features & Benefits at a Glance

• Exceptional strength for demanding applications with Grade 8 classification and 150,000 psi tensile strength.
• Superior corrosion resistance provided by the zinc yellow-chromate plating, extending service life in harsh environments.
• Reliable, fine-thread engagement with UNF 5/8"-18 threads and Class 2A fit for secure, vibration-resistant connections.
• Optimized for high-torque installation thanks to the external hex drive and robust hex head design.
• Full threading for maximum grip length, ensuring consistent clamping force across the entire fastener.
• High hardness rating of Rockwell C33 for excellent wear resistance and durability.
• Guaranteed compliance with industry standards including ASME B18.2.1 and SAE J429 for consistent quality and performance.

Professional Applications & Engineering Value

This Grade 8 hex head screw is engineered to solve critical challenges in heavy machinery, construction, and automotive assemblies where joint failure is not an option. The high-strength steel core, combined with the UNF fine thread and Class 2A fit, provides superior resistance to vibrational loosening and ensures precise, reliable fastening in high-stress environments. The zinc yellow-chromate plating offers a robust barrier against corrosion, significantly enhancing the fastener's longevity in outdoor or chemically aggressive settings. Its external hex drive and fully threaded design allow for efficient installation and maximum load distribution, making it an indispensable component for structural connections, engine components, and industrial equipment requiring 150,000 psi tensile strength.

Specification Summary & Compliance

This fastener features a 5/8"-18 UNF fine thread with a Class 2A thread fit for precise dimensional accuracy. It is manufactured from high-strength steel, heat-treated to Grade 8 standards, achieving a tensile strength of 150,000 psi and a hardness of Rockwell C33. The product is zinc yellow-chromate plated for corrosion protection and is fully threaded with a right-hand thread direction. Compliance is confirmed with ASME B18.2.1 and SAE J429 specifications, ensuring it meets rigorous industrial and engineering requirements for performance and safety.