S-91771A862 1/2"-13 x 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 tensile strength rated at 80,000 psi ensures reliable performance under heavy loads and vibration
• Precise Class 2A thread fit provides consistent engagement and reduces cross-threading risks during installation
• Fully threaded design offers maximum grip length and uniform stress distribution across the entire fastener
• Standard 82° countersink angle creates flush surface finishes for improved aesthetics and safety
• Rockwell B80 hardness maintains thread integrity and prevents stripping during repeated installations
• Phillips No. 4 drive compatibility enables efficient installation with common industrial tools

Professional Applications & Engineering Value

These 1/2"-13 UNC flat head screws deliver critical performance advantages for demanding industrial applications where corrosion resistance and structural integrity are paramount. The passivated 18-8 stainless steel construction provides superior protection against chemical exposure and environmental factors, making them ideal for marine equipment, food processing machinery, and outdoor structural assemblies. The coarse UNC thread pattern ensures rapid installation and reliable holding power in various materials, while the fully threaded design distributes clamping forces evenly to prevent joint failure. The standard 82° countersink angle allows for seamless flush mounting in precision applications where surface smoothness and aerodynamic profiles are essential. These industrial fasteners solve common engineering challenges including vibration-induced loosening, material compatibility issues, and maintenance accessibility requirements.

Specification Summary & Compliance

Manufactured to exacting ASME B18.6.3 standards with Class 2A thread fit tolerance for consistent dimensional accuracy. The UNC coarse thread profile (1/2"-13) ensures reliable engagement in various materials. Full compliance with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) environmental regulations, confirming adherence to international safety and sustainability requirements. The inch system measurement guarantees compatibility with North American industrial specifications and replacement part inventories.