S-92800A286 5/8"-18 x 5 1/2" 18-8 Stainless Steel Hex Head Screws

Key Features & Benefits at a Glance

• Exceptional corrosion resistance from 18-8 Stainless Steel construction, ideal for harsh environments and long-term reliability.
• High mechanical strength with 80,000 psi tensile strength and Rockwell B70 hardness for demanding, heavy-duty applications.
• Precise, fine-thread engagement with a UNF Class 2A thread fit, ensuring secure fastening and vibration resistance.
• Optimized for high-torque installation thanks to the external hex drive and 15/16" head width for a solid tool grip.
• Versatile partial threading with a 1 1/2" minimum thread length allows for unthreaded shank strength where needed.
• Full regulatory compliance with RoHS 3 and REACH, making it suitable for global industrial supply chains.
• Right-hand thread direction provides standard, intuitive installation for efficient assembly line operations.

Professional Applications & Engineering Value

This 5/8"-18 UNF hex head screw is engineered to solve critical challenges in industrial assembly and machinery. The 18-8 Stainless Steel material provides excellent resistance to rust and corrosion, making it a superior choice for outdoor equipment, marine applications, and chemical processing plants where environmental factors degrade lesser fasteners. The fine UNF thread and Class 2A fit offer superior clamping force and vibration resistance compared to coarse threads, which is essential for maintaining integrity in dynamic loads. The partially threaded design ensures that the unthreaded shank bears shear loads effectively, preventing joint failure. This combination of a high-strength external hex drive and robust material makes it a reliable, long-lasting fastener for structural frameworks, heavy machinery, and precision equipment requiring dependable, repeatable performance.

Specification Summary & Compliance

This screw conforms to UNF (Unified National Fine) thread standards with a Class 2A thread fit for consistent, precise assembly. It is manufactured to meet RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) compliance, ensuring it is free from hazardous substances and suitable for use in regulated markets. The dimensional accuracy, including the thread diameter of 0.625" and fine thread spacing, is maintained to industrial standards for reliable performance in inch-system applications.