S-91771A912 5/16"-18 x 6" 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, ideal for harsh industrial environments
• Exceptional mechanical strength with 80,000 psi tensile strength and Rockwell B80 hardness for reliable load-bearing performance
• Precise flush mounting enabled by the 82° countersink angle and standard flat head profile for seamless surface integration
• Optimized drive engagement through the Phillips No. 4 drive design, reducing cam-out risks during high-torque installation
• Consistent threading performance with fully threaded UNC coarse pattern and Class 2A fit for rapid assembly and vibration resistance
• Regulatory compliance assurance meeting ASME B18.6.3 specifications plus RoHS 3 and REACH environmental standards
• Versatile right-hand coarse threading providing excellent holding power in various materials including metal and hardwood

Professional Applications & Engineering Value

Engineered for demanding industrial applications, these flat head screws deliver critical advantages in machinery assembly, structural frameworks, and equipment manufacturing. The passivated 18-8 stainless steel construction provides exceptional resistance to oxidation and chemical exposure, significantly extending service life in corrosive environments. The combination of 80,000 psi tensile strength and Rockwell B80 hardness ensures reliable performance under sustained mechanical stress, while the fully threaded UNC coarse pattern with Class 2A fit guarantees secure fastening in both soft and hard materials. The 82° countersink angle and standard flat head profile enable flush surface mounting, eliminating protrusions that could interfere with moving components or create safety hazards in high-traffic industrial settings.

Specification Summary & Compliance

This 5/16"-18 UNC flat head screw maintains precise Class 2A thread fit tolerances with coarse thread spacing and right-hand threading. Manufacturing complies with ASME B18.6.3 standards for dimensional accuracy and mechanical properties. Environmental compliance is verified through RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) regulations, ensuring restricted substance adherence for global industrial applications.