S-90273A571 1/4"-20 x 3 1/2" ASME B18.6.3 Steel Phillips Flat Head Screws

Key Features & Benefits at a Glance

• Superior corrosion resistance with zinc-plated steel construction, extending service life in demanding industrial environments
• High-torque installation capability through Phillips No. 3 drive design, preventing cam-out during assembly
• Exceptional tensile strength rated at 60,000 psi with Rockwell B70 hardness for reliable performance under heavy loads
• Optimized thread engagement with UNC coarse threading and Class 2A fit, ensuring secure fastening in various materials
• Flush mounting compatibility featuring standard 82° countersink angle for seamless surface integration
• Controlled thread distribution through partial threading design, providing optimal grip strength where needed
• Regulatory compliance assurance meeting ASME B18.6.3 specifications and environmental standards including RoHS 3 and REACH

Professional Applications & Engineering Value

This zinc-plated steel flat head screw delivers critical engineering solutions for industrial assembly challenges. The combination of 60,000 psi tensile strength and Rockwell B70 hardness ensures reliable performance in structural applications where vibration resistance and load-bearing capacity are paramount. The UNC coarse thread configuration provides superior pull-out resistance in wood, plastic, and soft metals, while the partial threading design concentrates engagement strength precisely where needed. The 82° countersink angle creates seamless flush mounting in machinery, electrical enclosures, and fabricated metal structures. With Phillips No. 3 drive compatibility, installation efficiency is maximized across production environments, making these industrial screws ideal for manufacturing equipment, automotive assemblies, and construction applications requiring dependable heavy-duty fasteners.

Specification Summary & Compliance

This flat head Phillips screw maintains precise Class 2A thread fit tolerances with 1/4"-20 UNC coarse threading and right-hand orientation. Manufacturing conforms to ASME B18.6.3 specifications, ensuring dimensional accuracy and performance reliability. The product is fully compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) environmental regulations, meeting the latest standards for industrial fastener safety and sustainability.