S-91781A585 5/16"-18 x 1 1/4" ASME B18.6.3 Stainless Steel Slotted 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
• Exceptional mechanical strength delivering 80,000 psi tensile strength and Rockwell B80 hardness for reliable load-bearing performance
• Precision threading with UNC coarse thread and Class 2A fit ensures easy installation and secure fastening
• Full threading design provides maximum grip length and uniform stress distribution across the entire fastener
• Standard 82° countersink angle allows for flush mounting in various applications without protruding heads
• Slotted drive compatibility offers straightforward installation with common hand tools
• Comprehensive compliance with ASME B18.6.3 standards and environmental regulations including RoHS 3 and REACH

Professional Applications & Engineering Value

This 18-8 stainless steel flat head screw delivers exceptional engineering value across demanding industrial applications. The combination of 80,000 psi tensile strength and Rockwell B80 hardness provides reliable performance in high-stress environments, while the passivated finish significantly enhances corrosion resistance, making it ideal for marine, chemical processing, and outdoor applications. The UNC coarse threading with Class 2A fit ensures quick assembly and vibration resistance, reducing maintenance requirements. The flat head design with 82° countersink creates smooth, flush surfaces in machinery, equipment panels, and structural components, preventing snagging and improving safety. These fully threaded screws offer uniform clamping force distribution, making them perfect for industrial fastening solutions requiring both strength and corrosion protection.

Specification Summary & Compliance

This fastener maintains precise Class 2A thread fit with 5/16"-18 UNC coarse threading and right-hand thread direction, manufactured to exact dimensional requirements. The screw complies with ASME B18.6.3 specifications for dimensional standards and meets critical environmental regulations including RoHS 3 (2015/863/EU) compliance and REACH (EC 1907/2006) compliance, ensuring suitability for global industrial applications with strict material restrictions.