S-92620A252 5/8"-18 x 2 3/4" 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 and Grade 8 classification, this screw reliably handles extreme mechanical stresses in demanding environments.
• Superior Corrosion Resistance: Zinc yellow-chromate plating provides durable protection against rust and environmental degradation, extending service life in harsh conditions.
• Precision Thread Engagement: Class 2A thread fit ensures consistent, secure fastening with reduced risk of cross-threading or loosening under vibration.
• Optimized Drive Efficiency: External hex head design allows for high-torque installation using standard tools, speeding up assembly in industrial applications.
• Enhanced Material Durability: Rockwell C33 hardness maintains structural integrity under repeated loading, minimizing wear and deformation over time.
• Versatile Partial Threading: Combines strong grip in threaded sections with smooth shank alignment, ideal for components requiring precise clamping force distribution.
• Regulatory Compliance Assurance: Meets ASME B18.2.1, SAE J429, RoHS 3, and REACH standards, ensuring suitability for regulated industries and global supply chains.

Professional Applications & Engineering Value

This Grade 8 hex head screw delivers critical performance in heavy-duty industrial applications where failure is not an option. The 5/8"-18 UNF fine thread configuration provides superior resistance to vibrational loosening compared to coarse threads, making it ideal for dynamic machinery, structural steel connections, and high-pressure equipment. The zinc yellow-chromate plating creates a sacrificial barrier that significantly outperforms standard zinc coatings in corrosive environments including manufacturing facilities, outdoor structures, and automotive assemblies. With partial threading, engineers can precisely control clamping force distribution while the external hex drive accommodates high installation torque requirements. These steel fasteners solve common engineering challenges including joint integrity maintenance under cyclic loading, corrosion-induced premature failure, and compliance with international mechanical standards.

Specification Summary & Compliance

This fastener maintains Class 2A thread fit tolerances per UNF specifications, ensuring precise engagement with mating components. Manufacturing conforms to ASME B18.2.1 and SAE J429 standards for dimensional accuracy and mechanical properties. The product is fully compliant with RoHS 3 (2015/863/EU) restrictions on hazardous substances and REACH (EC 1907/2006) regulations regarding chemical safety, making it suitable for international industrial markets with strict environmental requirements.