S-91771A572 1/4"-20 x 5 1/2" 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 for long-lasting performance in harsh environments
• Exceptional mechanical strength with 80,000 psi tensile strength and Rockwell B80 hardness for reliable load-bearing applications
• Perfect flush mounting enabled by standard 82° countersink angle and flat head design for seamless surface integration
• Optimized drive engagement with Phillips No. 3 drive style providing secure installation and reduced cam-out risk
• Reliable thread performance through UNC coarse threading and Class 2A fit ensuring consistent engagement and vibration resistance
• Full-length threading offering maximum grip strength and adjustment flexibility across the entire 5½" length
• Regulatory compliance meeting ASME B18.6.3 specifications and environmental standards for global industrial use

Professional Applications & Engineering Value

These 1/4"-20 flat head screws deliver exceptional engineering value through their passivated 18-8 stainless steel construction, which provides superior corrosion resistance critical for industrial environments exposed to moisture, chemicals, and temperature variations. The fully threaded design with UNC coarse threading ensures maximum holding power across the entire 5½" length, making them ideal for heavy-duty applications requiring reliable fastening in machinery, structural assemblies, and equipment manufacturing. The 82° countersink angle and flat head profile solve critical flush-mounting challenges, eliminating protrusions that could interfere with moving parts or create safety hazards. The Phillips drive system offers efficient installation while the Class 2A thread fit maintains precise tolerances for consistent performance in vibration-prone applications, from industrial machinery to construction equipment.

Specification Summary & Compliance

This flat head Phillips screw features precise Class 2A thread fit with 1/4"-20 UNC coarse threads and right-hand direction. Manufacturing complies with ASME B18.6.3 specifications, ensuring dimensional accuracy and performance reliability. The product meets RoHS 3 (2015/863/EU) compliance for hazardous substance restrictions and REACH (EC 1907/2006) regulations for chemical safety, making it suitable for global industrial markets and environmentally conscious applications.