S-90585A997 5/16"-18 x 1 3/8" ASME B18.3 Stainless Steel Hex Drive Flat Head Screws

Key Features & Benefits at a Glance

• Superior corrosion resistance with 316 stainless steel construction for extended service life in 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 thread fit ensuring secure fastening and vibration resistance in critical applications
• Optimized flush mounting with 82° countersink angle and flat head design for smooth surface finishes and reduced snagging
• Enhanced installation efficiency with 3/16" hex drive providing superior torque transmission and reduced tool slippage
• Full-threaded design offering maximum grip length and uniform stress distribution across the entire fastener
• Regulatory compliance assurance meeting ASME B18.3 standards and environmental regulations including RoHS 3 and REACH

Professional Applications & Engineering Value

These 316 stainless steel flat head screws deliver exceptional value in demanding industrial applications where corrosion resistance and mechanical reliability are paramount. The combination of UNC coarse threading and Class 3A thread fit ensures rapid installation and secure fastening in materials prone to vibration loosening. The passivated finish enhances surface durability while maintaining the alloy's inherent chemical resistance, making these hex drive screws ideal for marine equipment, chemical processing plants, and food processing machinery. The fully threaded design provides consistent clamping force distribution, while the standardized 82° countersink angle ensures proper seating in precision-machined components, eliminating protrusion issues in automated assembly systems.

Specification Summary & Compliance

Manufactured to ASME B18.3 specifications with Class 3A thread fit tolerance for precision engagement. Features 5/16"-18 UNC coarse threads with complete threading along the 1 3/8" length. Compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) environmental regulations. The passivated surface treatment meets industry standards for corrosion protection while maintaining dimensional stability across the specified head diameter tolerance range of -0.056" to 0".