S-90585A056 5/16"-18 x 2 1/4" ASME B18.3 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 chemical and marine environments
• Exceptional mechanical strength with 70,000 psi tensile strength and Rockwell B55 hardness for reliable performance under heavy loads
• Precision thread engagement with Class 3A fit and UNC coarse threads ensuring secure fastening and vibration resistance
• Flush mounting capability with standard 82° countersink angle and flat head design for smooth surface finishes
• Easy installation and removal using standard 3/16" hex drive tools for efficient maintenance operations
• Full regulatory compliance meeting ASME B18.3 specifications, RoHS 3, and REACH environmental standards
• Complete thread coverage with fully threaded 2-1/4" length providing maximum grip and load distribution

Professional Applications & Engineering Value

These 316 stainless steel flat head screws deliver exceptional performance in demanding industrial applications where corrosion resistance and structural integrity are paramount. The combination of UNC coarse threads and Class 3A thread fit provides superior vibration resistance in machinery, automotive, and marine equipment. The passivated finish enhances the natural corrosion resistance of 316 stainless steel, making these fasteners ideal for chemical processing plants, offshore installations, and food processing equipment where exposure to corrosive elements is constant. The 82° countersink angle ensures flush mounting in precision assemblies, while the hex drive design allows for high-torque installation without slippage. These screws solve critical engineering challenges by maintaining structural integrity in high-stress applications while meeting stringent environmental compliance requirements.

Specification Summary & Compliance

Manufactured to exacting ASME B18.3 specifications with Class 3A thread fit for precision tolerance. Features 5/16"-18 UNC coarse threads with full threading along the 2-1/4" length. Compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) environmental regulations. Mechanical properties include 70,000 psi tensile strength and Rockwell B55 hardness for consistent performance in industrial applications.