S-91771A580 5/16"-18 x 5/8" ASME B18.6.3 Stainless Steel Phillips Flat Head Screws

Key Features & Benefits at a Glance

• Exceptional corrosion resistance with passivated 18-8 stainless steel construction, ideal for harsh industrial environments
• Superior mechanical strength with 80,000 psi tensile strength and Rockwell B80 hardness for reliable load-bearing performance
• Precision thread engagement through Class 2A thread fit and UNC coarse threading, ensuring secure fastening and vibration resistance
• Efficient flush installation with standard 82° countersink angle and flat head design for seamless surface integration
• Optimized drive performance using Phillips No. 4 drive style, providing effective torque transfer and reduced cam-out risk
• Full-threaded reliability across the entire 5/8" length, delivering maximum grip and uniform stress distribution
• Regulatory compliance assurance meeting ASME B18.6.3, RoHS 3, and REACH standards for quality and environmental safety

Professional Applications & Engineering Value

Engineered for demanding industrial applications, these 5/16"-18 UNC flat head screws address critical fastening challenges in machinery, equipment assembly, and structural frameworks. The passivated 18-8 stainless steel provides outstanding resistance to oxidation and chemical exposure, significantly extending service life in corrosive environments. The fully threaded right-hand design with coarse UNC threading ensures rapid installation and superior holding power, while the standard 82° countersink angle enables seamless flush mounting in precision components. This combination of material durability and thread engineering minimizes maintenance frequency and prevents joint failure under dynamic loads, making these Phillips drive screws a trusted solution for OEM and MRO requirements across manufacturing, automotive, and construction sectors.

Specification Summary & Compliance

This flat head screw maintains precise dimensional accuracy with Class 2A thread fit and UNC coarse thread standards, ensuring consistent performance in threaded assemblies. Manufacturing and quality control adhere to ASME B18.6.3 specifications, while environmental compliance is verified through RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) regulations, confirming the absence of restricted hazardous substances. These certifications support global supply chain integration and sustainable procurement practices.