S-91772A127 4-40 x 2 3/4" ASME B18.6.3 Stainless Steel Pan Head Phillips Screws

Key Features & Benefits at a Glance

• Superior corrosion resistance with passivated 18-8 stainless steel construction, ensuring long-term reliability in harsh environments
• Optimized load distribution through the pan head design, providing excellent clamping force and reducing surface damage
• Enhanced installation efficiency with Phillips No. 1 drive, allowing quick and secure fastening in automated or manual assembly
• Reliable thread engagement with Class 2A thread fit and UNC coarse spacing, preventing cross-threading and ensuring consistent performance
• High mechanical strength delivering 70,000 psi tensile strength and Rockwell B70 hardness for demanding industrial applications
• Versatile partial threading enabling precise grip length control where full threading isn't required
• Full regulatory compliance meeting ASME B18.6.3 standards and environmental regulations including RoHS 3 and REACH

Professional Applications & Engineering Value

These 4-40 UNC partially threaded pan head screws deliver exceptional engineering value in precision assemblies where corrosion resistance and mechanical reliability are critical. The passivated 18-8 stainless steel construction provides superior protection against oxidation and chemical exposure, making them ideal for industrial equipment, electronic enclosures, and marine applications. The partially threaded design allows unthreaded shank sections to act as precision dowels or pivot points, while the coarse UNC thread spacing ensures rapid installation and superior vibration resistance. With 70,000 psi tensile strength, these fasteners maintain structural integrity under dynamic loads, and the Phillips drive system enables efficient high-volume assembly operations without compromising fastener integrity.

Specification Summary & Compliance

This fastener features Class 2A thread fit tolerance per UNC standards with coarse thread spacing for reliable engagement. Manufacturing complies with ASME B18.6.3 specifications for dimensional accuracy and performance. The product meets RoHS 3 (2015/863/EU) compliance for hazardous substance restriction and REACH (EC 1907/2006) compliance for chemical safety, ensuring environmental responsibility in industrial supply chains.