S-91771A602 5/16"-18 x 5" ASME B18.6.3 Stainless Steel Phillips Flat Head Screws

Key Features & Benefits at a Glance

• Superior corrosion resistance from passivated 18-8 stainless steel construction, ensuring long-term reliability in harsh environments
• Exceptional 80,000 psi tensile strength provides reliable fastening integrity for demanding industrial applications
• Optimized UNC coarse threading delivers faster installation and reduced cross-threading risk compared to fine thread alternatives
• Precision Class 2A thread fit ensures consistent engagement and vibration resistance in assembled components
• Standard 82° countersink angle enables flush mounting with common chamfered holes for clean, professional finishes
• Rockwell B80 hardness rating maintains thread form and drive integrity through repeated installation cycles
• Comprehensive regulatory compliance meets ASME B18.6.3, RoHS 3, and REACH standards for global manufacturing acceptance

Professional Applications & Engineering Value

These 5/16"-18 UNC flat head screws deliver critical performance advantages for industrial assembly applications where corrosion resistance and structural integrity are paramount. The passivated 18-8 stainless steel construction provides exceptional protection against oxidation and chemical exposure, making these flat head screws ideal for marine equipment, food processing machinery, and outdoor structural applications. The partially threaded design with 1-1/2" minimum thread length concentrates engagement where needed while the Phillips No. 4 drive offers familiar, efficient installation. The combination of 80,000 psi tensile strength and coarse UNC threading ensures reliable performance in vibration-prone environments where fastener loosening poses operational risks.

Specification Summary & Compliance

Manufactured to precise dimensional standards with Class 2A thread fit tolerance ensuring consistent mating with corresponding nuts and threaded holes. The UNC coarse thread profile (5/16"-18) conforms to unified thread standards while the 82° countersink angle matches industry-standard chamfer preparations. Full compliance with ASME B18.6.3 mechanical specifications, RoHS 3 (2015/863/EU) hazardous substance restrictions, and REACH (EC 1907/2006) chemical safety regulations ensures suitability for global industrial supply chains.