S-90273A554 1/4"-20 x 3" ASME B18.6.3 Steel Phillips Flat Head Screws

Key Features & Benefits at a Glance

• Exceptional corrosion resistance with zinc-plated steel construction, ensuring long-term reliability in demanding environments
• Superior holding power from 60,000 psi tensile strength and Rockwell B70 hardness, preventing fastener failure under stress
• Optimized installation efficiency with No. 3 Phillips drive and standard 82° countersink angle for flush, secure seating
• Reliable thread engagement through UNC coarse threading and Class 2A fit, reducing cross-threading risks in industrial assemblies
• Controlled fastening precision with partial threading design, minimizing material stress in critical joint applications
• Broad regulatory compliance meeting ASME B18.6.3, RoHS 3, and REACH standards for global project suitability
• Versatile right-hand threading compatible with standard UNC nuts and tapped holes for simplified inventory management

Professional Applications & Engineering Value

Engineered for industrial and construction applications, these zinc-plated steel flat head screws address critical fastening challenges where surface flushness and corrosion resistance are paramount. The UNC coarse thread configuration ensures rapid installation in wood, metal, and composite materials while the partial threading design provides concentrated clamping force at the joint interface. With 82° countersink angle compatibility, these screws create seamless surfaces in machinery, structural frameworks, and equipment assemblies. The zinc plating delivers essential protection against environmental degradation, making these Phillips drive screws ideal for both indoor and outdoor applications requiring durable, maintenance-free fastening solutions.

Specification Summary & Compliance

Manufactured to precise dimensional standards with Class 2A thread fit and UNC coarse thread specifications ensuring consistent performance across applications. These flat head screws strictly conform to ASME B18.6.3 mechanical and dimensional requirements, while meeting RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) environmental compliance standards for hazardous substance restrictions. The combination of 60,000 psi tensile strength and Rockwell B70 hardness guarantees mechanical integrity in high-stress fastening scenarios.