S-92620A253 5/8"-18 x 5 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 capacity with 150,000 psi tensile strength for reliable performance in demanding applications
• Superior corrosion resistance through zinc yellow-chromate plating that protects against harsh industrial environments
• Precise thread engagement with Class 2A thread fit ensuring consistent installation and vibration resistance
• Enhanced durability from Rockwell C33 hardness that maintains structural integrity under heavy stress
• Optimized torque transmission through the external hex drive design for secure fastening and easy installation
• Reduced weight and material usage with partial threading while maintaining full strength in critical engagement areas
• Industry-standard compatibility with UNF fine threads that provide superior holding power in high-vibration applications

Professional Applications & Engineering Value

Engineered for heavy-duty industrial applications, these Grade 8 hex head screws deliver exceptional performance where reliability is critical. The 5/8"-18 UNF fine thread configuration provides superior resistance to vibration loosening, making them ideal for machinery, structural steel connections, and equipment subjected to dynamic loads. The zinc yellow-chromate plating creates a protective barrier against corrosion in challenging environments, while the partially threaded design concentrates strength where it's needed most. These high-strength steel screws solve common engineering challenges by combining maximum clamping force with environmental protection, ensuring long-term fastener integrity in construction, manufacturing, and heavy equipment applications.

Specification Summary & Compliance

This 5/8"-18 UNF hex head screw features precise Class 2A thread fit tolerances and meets ASME B18.2.1 and SAE J429 manufacturing specifications. The fastener demonstrates full compliance with RoHS 3 (2015/863/EU) environmental standards and REACH (EC 1907/2006) regulations, ensuring safe use across industrial sectors. With dimensions including a 15/16" head width, 25/64" head height, and 5 1/2" overall length, these screws maintain strict quality control throughout production.