S-91771A589 5/16"-18 x 1 3/4" ASME B18.6.3 Stainless Steel Phillips Flat Head Screws

Key Features & Benefits at a Glance

• Superior corrosion resistance with passivated 18-8 stainless steel construction, ideal for harsh industrial environments
• Exceptional mechanical strength with 80,000 psi tensile strength and Rockwell B80 hardness for heavy-duty applications
• Reliable thread engagement through Class 2A thread fit and UNC coarse threading for secure fastening
• Optimized flush installation with standard 82° countersink angle and flat head design for smooth surface finishing
• Efficient installation using Phillips No. 4 drive style for common tool compatibility and reduced assembly time
• Full-threaded design ensures maximum grip length and uniform stress distribution across the entire fastener
• Regulatory compliance meets ASME B18.6.3 standards and environmental regulations for global industrial use

Professional Applications & Engineering Value

This 5/16"-18 UNC flat head screw delivers exceptional engineering value in demanding industrial applications where corrosion resistance and mechanical reliability are critical. The passivated 18-8 stainless steel construction provides superior protection against chemical exposure and environmental degradation, making it ideal for marine equipment, food processing machinery, and outdoor structures. The combination of 80,000 psi tensile strength and Class 2A thread fit ensures secure fastening in high-vibration environments, while the fully threaded design maximizes load distribution across joined materials. The 82° countersink angle and flat head profile enable flush mounting in precision assemblies, eliminating protrusions that could interfere with mechanical operation. These industrial screws solve common engineering challenges by providing durable, compliant fastening solutions that maintain integrity under continuous stress and corrosive conditions.

Specification Summary & Compliance

This fastener maintains Class 2A thread fit tolerance with UNC coarse threading (5/16"-18) and features a fully threaded design measuring 1 3/4" in length. Manufacturing and dimensional specifications strictly adhere to ASME B18.6.3 standards, ensuring interchangeability and reliability across industrial applications. The product is fully compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) environmental regulations, confirming its suitability for global markets and environmentally conscious manufacturing operations.