S-92210A590 5/16"-18 x 1 7/8" ASME B18.3, ASTM F879 Stainless Steel Hex Drive Flat Head Screws

Key Features & Benefits at a Glance

• Superior corrosion resistance with 18-8 stainless steel construction and passivated finish, ideal for harsh environments.
• High-strength performance with 70,000 psi tensile strength and Rockwell B55 hardness for demanding applications.
• Secure, high-precision fit thanks to Class 3A thread fit and UNC coarse threading, ensuring reliable fastening.
• Easy, high-torque installation with a 3/16" hex drive, reducing assembly time and tool slippage.
• Flush, low-profile seating with an 82° countersink angle and standard flat head profile for smooth surfaces.
• Full thread engagement along the 1-7/8" length, providing maximum grip and load distribution.
• Guaranteed compliance and safety meeting ASME B18.3, ASTM F879, RoHS 3, and REACH standards.

Professional Applications & Engineering Value

This 18-8 stainless steel flat head screw is engineered to solve critical industrial challenges, such as vibration loosening and corrosion-induced failure. Its UNC coarse thread and Class 3A thread fit deliver exceptional holding power in metals and plastics, while the hex drive allows for high-torque applications without cam-out. The passivated finish enhances durability in moist or chemical-exposed settings, making it ideal for machinery, automotive, and structural assemblies. Fully threaded for uniform stress, it ensures long-term reliability in heavy-duty fastening scenarios, reducing maintenance and replacement costs.

Specification Summary & Compliance

This screw adheres to ASME B18.3 and ASTM F879 specifications, with precise Class 3A thread fit and UNC coarse threading (5/16"-18). Dimensions include a 1-7/8" length, 0.656" head diameter, and 82° countersink angle. It is fully compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006), ensuring environmental and safety standards are met for industrial use.