S-91771A115 4-40 x 1" 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 for long-lasting performance in harsh environments
• Exceptional mechanical strength with 80,000 psi tensile strength and Rockwell B80 hardness for reliable load-bearing capabilities
• Precision thread engagement through Class 2A UNC coarse threads ensuring consistent fastening and vibration resistance
• Optimized flush mounting with standard 82° countersink angle and flat head design for seamless surface integration
• Enhanced driving efficiency with Phillips #1 drive providing secure torque transfer and reduced cam-out risk
• Full-threaded design delivering maximum grip length and uniform stress distribution across the entire 1" length
• Regulatory compliance assurance meeting ASME B18.6.3 standards and environmental regulations for global industrial applications

Professional Applications & Engineering Value

These 4-40 UNC flat head screws deliver critical engineering solutions where corrosion resistance and structural integrity are paramount. The passivated 18-8 stainless steel construction provides exceptional protection against oxidation and chemical exposure, making them ideal for industrial equipment, marine components, and food processing machinery. The fully threaded UNC coarse thread design ensures maximum engagement in both metallic and composite materials, while the 82° countersink angle creates secure, flush-mounted assemblies that eliminate protrusions in precision applications. With 80,000 psi tensile strength, these Phillips #1 drive fasteners maintain clamping force under dynamic loads and vibration, addressing common failure points in manufacturing equipment and electronic enclosures.

Specification Summary & Compliance

Manufactured to ASME B18.6.3 specifications with Class 2A thread fit tolerance for consistent mating with standard UNC nuts and threaded holes. The 4-40 UNC coarse thread configuration provides optimal performance in most materials, while the right-hand thread direction and standard flat head profile ensure compatibility with conventional installation tools. Compliance with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) regulations guarantees environmental responsibility and unrestricted use in global markets.