S-90273A572 1/4"-20 x 4" 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 load-bearing capacity with 60,000 psi tensile strength and Rockwell B70 hardness for reliable performance under stress
• Optimized flush mounting with standard 82° countersink angle and flat head design for seamless surface integration
• Secure fastening efficiency through Phillips No. 3 drive and coarse UNC threading for rapid installation and vibration resistance
• Precision thread engagement with Class 2A fit ensuring consistent mating with nuts and threaded components
• Versatile partial threading design providing both gripping strength and clearance where needed
• Full regulatory compliance meeting ASME B18.6.3, RoHS 3, and REACH standards for quality assurance

Professional Applications & Engineering Value

This zinc-plated steel flat head screw delivers exceptional engineering value in industrial assembly applications where flush surface mounting and corrosion resistance are critical. The combination of 60,000 psi tensile strength and Rockwell B70 hardness ensures reliable performance in structural applications, machinery assembly, and equipment manufacturing. The 1/4-20 UNC coarse thread with Class 2A fit provides excellent engagement in various materials, while the Phillips No. 3 drive enables efficient installation without specialized tools. The partially threaded design offers optimal clamping force distribution, making these flat head screws ideal for metal fabrication, automotive components, and industrial machinery where vibration resistance and long-term durability are essential requirements.

Specification Summary & Compliance

This 1/4-20 x 4" flat head screw features precise Class 2A thread fit with UNC coarse thread spacing and right-hand threading. Manufactured to ASME B18.6.3 specifications with 82° countersink angle and partial threading design. Fully compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) environmental regulations, ensuring safe use across various industrial applications while maintaining consistent dimensional accuracy and performance standards.