S-90585A131 6-40 x 1/4" ASME B18.3, ASTM F879 Stainless Steel Hex Drive Flat Head Screws

Key Features & Benefits at a Glance

• Superior corrosion resistance with 316 Stainless Steel construction and passivated finish, ideal for harsh environments and extended service life.
• Exceptional mechanical strength offering 70,000 psi tensile strength and Rockwell B55 hardness for reliable, high-stress fastening.
• Precision thread engagement with Class 3A fit and UNF fine threads, ensuring secure, vibration-resistant connections.
• Streamlined flush installation featuring a standard 82° countersink angle and flat head for a smooth, professional finish.
• Efficient assembly and maintenance enabled by a 5/64" hex drive, allowing for high-torque application in confined spaces.
• Guaranteed dimensional consistency manufactured to ASME B18.3 specifications for reliable interchangeability and performance.
• Compliance with global standards including RoHS 3 and REACH, ensuring safety and environmental responsibility.

Professional Applications & Engineering Value

This 6-40 UNF flat head screw is engineered to solve critical challenges in precision industries. The 316 Stainless Steel material provides outstanding resistance to chemicals and saltwater corrosion, making it indispensable for marine, chemical processing, and food-grade equipment. Its fully threaded design and Class 3A thread fit deliver maximum grip and clamping force, preventing loosening under vibration in machinery and aerospace assemblies. The 82° countersink angle and flat head profile allow for a seamless, flush mount, essential for applications where aerodynamics or safety require no protruding hardware. Combined with a hex drive for secure tool engagement, this screw offers a dependable industrial fastening solution that enhances product integrity and reduces maintenance cycles.

Specification Summary & Compliance

This screw adheres to strict dimensional tolerances, including a Class 3A thread fit for precision and a head diameter tolerance of -0.044" to 0". It is manufactured in accordance with ASME B18.3 specifications and is fully RoHS 3 (2015/863/EU) Compliant and REACH (EC 1907/2006) Compliant, ensuring it meets rigorous international safety and environmental standards for industrial use.