S-91735A396 1/4"-28 x 1/2" ASME B18.6.3 Stainless Steel Pan Head Phillips Screws

Key Features & Benefits at a Glance

• Superior corrosion resistance with 316 stainless steel construction and passivated finish for extended service life in harsh environments
• Exceptional mechanical strength delivering 80,000 psi tensile strength and Rockwell B85 hardness for reliable load-bearing performance
• Precision thread engagement with Class 2A fit and UNF fine threads ensuring secure, vibration-resistant fastening
• Optimized drive efficiency featuring No. 3 Phillips drive for easy installation with standard tools
• Enhanced seating stability with rounded pan head design providing consistent surface contact and reduced stress concentration
• Full-threaded construction maximizing grip length and pull-out resistance across the entire fastener
• Regulatory compliance assurance meeting ASME B18.6.3 specifications and environmental standards including RoHS 3 and REACH

Professional Applications & Engineering Value

These 1/4-28 UNF rounded head screws deliver critical performance advantages in demanding industrial applications where corrosion resistance and mechanical reliability are paramount. The 316 stainless steel composition combined with passivated finish provides exceptional protection against chemical exposure, saltwater environments, and industrial contaminants, significantly extending service intervals in marine, chemical processing, and food equipment applications. The UNF fine thread configuration with Class 2A fit ensures precise engagement in tapped holes, minimizing the risk of cross-threading while providing superior vibration resistance in dynamic load conditions. The combination of 80,000 psi tensile strength and fully threaded design offers optimal clamp load distribution, making these Phillips drive screws ideal for critical assemblies requiring consistent fastening pressure and long-term joint integrity.

Specification Summary & Compliance

This rounded head screw features precise dimensional specifications including 1/4"-28 UNF fine threads with Class 2A thread fit tolerance, 0.492" head diameter, and 1/2" length. Manufacturing complies with ASME B18.6.3 standards for dimensional consistency and mechanical performance. The product is fully compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) environmental regulations, ensuring safe use in regulated industries and international markets.