S-91771A931 2-56 x 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, ideal for harsh industrial environments
• Exceptional mechanical strength with 80,000 psi tensile strength and Rockwell B80 hardness for reliable, long-term performance
• Precision thread engagement with UNC coarse threads and Class 2A fit ensuring easy installation and secure fastening
• Optimized flush mounting with standard flat head profile and 100° countersink angle for seamless surface integration
• Efficient drive compatibility with Phillips No. 1 drive for quick installation using standard tools
• Full-threaded design across the 1/2" length provides maximum grip and load distribution
• Regulatory compliance assurance meeting ASME B18.6.3 standards and environmental regulations for global applications

Professional Applications & Engineering Value

These 2-56 UNC flat head Phillips machine screws deliver critical performance advantages in demanding industrial settings. The passivated 18-8 stainless steel construction provides exceptional resistance to corrosion and chemical exposure, making them ideal for electronics assembly, machinery manufacturing, and outdoor equipment where environmental factors threaten fastener integrity. The combination of 80,000 psi tensile strength and Rockwell B80 hardness ensures reliable performance under vibration and load stress, while the fully threaded coarse UNC pattern with Class 2A fit guarantees precise engagement without cross-threading risks. The standard flat head profile with 100° countersink angle enables flush mounting in precision applications where surface protrusion is unacceptable, and the Phillips drive system provides efficient installation with common industrial tools.

Specification Summary & Compliance

This 2-56 UNC flat head machine screw features precise Class 2A thread fit with coarse thread spacing and right-hand thread direction. Manufacturing complies with ASME B18.6.3 specifications for dimensional accuracy and performance standards. The product meets RoHS 3 (2015/863/EU) compliance and REACH (EC 1907/2006) regulations regarding hazardous substances, ensuring environmental responsibility and global market acceptance for industrial fastener applications.