S-91771A191 8-32 x 5/16" 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 extended service life in harsh environments
• High tensile strength of 80,000 psi ensures reliable fastening performance under substantial mechanical loads
• Precision Class 2A thread fit provides smooth installation and consistent engagement in UNC coarse threaded applications
• Optimized 82° countersink angle enables flush mounting with standard countersunk holes for clean surface finishes
• Phillips No. 2 drive design offers efficient torque transfer and reduced cam-out during installation
• Full threading along the 5/16" length maximizes grip range and adjustment flexibility in assembly applications
• Comprehensive regulatory compliance including RoHS 3 and REACH ensures environmental and safety standards are met

Professional Applications & Engineering Value

These 8-32 UNC flat head Phillips screws deliver exceptional engineering value through their passivated 18-8 stainless steel composition, which provides outstanding corrosion resistance critical for industrial equipment, marine applications, and outdoor installations. The coarse thread design with Class 2A fit ensures rapid assembly and reliable performance in materials where fine threads might strip or fail. The 82° countersink angle combined with the flat head profile creates seamless surface integration, eliminating protrusions that could interfere with moving parts or create safety hazards. With 80,000 psi tensile strength and Rockwell B80 hardness, these fully threaded machine screws maintain structural integrity under vibration and dynamic loads, making them ideal for machinery assembly, electrical enclosures, and precision manufacturing applications where both strength and corrosion resistance are paramount.

Specification Summary & Compliance

Manufactured to exacting ASME B18.6.3 standards, these screws feature precision UNC coarse threads with Class 2A thread fit for consistent dimensional accuracy. The 5/16" length and fully threaded design provide uniform engagement characteristics. Compliance with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) regulations ensures environmental safety and restricted substance adherence, while the 82° countersink angle meets industry-standard recess requirements for proper seating in countersunk applications.