S-91771A566 1/4"-28 x 2" 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 reliable load-bearing performance
• Precise thread engagement through Class 2A thread fit and UNF fine threading, ensuring secure fastening in critical applications
• Optimized flush mounting with standard flat head profile and 82° countersink angle for seamless surface integration
• Efficient installation using Phillips No. 3 drive system, reducing tool slippage and assembly time
• Full-threaded design providing maximum grip length and uniform stress distribution along the entire 2" length
• Regulatory compliance assurance meeting ASME B18.6.3 specifications and environmental standards including RoHS 3 and REACH

Professional Applications & Engineering Value

This 1/4"-28 UNF flat head screw delivers exceptional engineering value in demanding industrial applications where corrosion resistance and mechanical reliability are paramount. The passivated 18-8 stainless steel construction provides superior protection against oxidation and chemical exposure, making it ideal for machinery, equipment manufacturing, and outdoor installations. The UNF fine thread configuration ensures precise thread engagement in thin materials and vibration-prone environments, while the fully threaded design maximizes holding power across the entire fastener length. The combination of 80,000 psi tensile strength and Rockwell B80 hardness provides dependable performance in high-stress applications, from assembly lines to structural frameworks, where fastener failure is not an option.

Specification Summary & Compliance

This flat head Phillips screw maintains Class 2A thread fit tolerance with 1/4"-28 UNF fine threading and right-hand thread direction. Manufacturing complies with ASME B18.6.3 specifications for dimensional accuracy and performance standards. The product is fully RoHS 3 (2015/863/EU) compliant and REACH (EC 1907/2006) compliant, meeting current environmental regulations for industrial use. Additional specifications include standard flat head profile, 82° countersink angle, and full threading along the 2" length.