S-90273A581 5/16"-18 x 3/4" ASME B18.6.3 Steel Phillips Flat Head Screws

Key Features & Benefits at a Glance

• Superior corrosion resistance with zinc-plated steel construction for extended service life in demanding environments
• Exceptional holding power with 60,000 psi tensile strength ensuring reliable fastening under heavy loads
• Optimized flush installation with standard 82° countersink angle for smooth, professional surface finishes
• Enhanced driving efficiency through Phillips No. 4 drive design reducing cam-out and tool slippage
• Reliable thread engagement with Class 2A thread fit and coarse UNC threading for quick assembly and vibration resistance
• Full-threaded design providing maximum grip length and uniform stress distribution across the entire fastener
• Industry-standard compliance meeting ASME B18.6.3 specifications for consistent quality and interchangeability

Professional Applications & Engineering Value

These 5/16"-18 UNC flat head screws deliver critical engineering solutions where flush surface mounting and high tensile strength are paramount. The zinc-plated steel construction provides essential corrosion protection for industrial equipment, machinery assemblies, and structural frameworks exposed to moderate environmental conditions. The coarse UNC threading ensures rapid installation and superior resistance to vibrational loosening in dynamic applications. With Rockwell B70 hardness and fully threaded design, these Phillips drive screws maintain structural integrity while the standardized 82° countersink angle guarantees seamless integration into prepared surfaces. Ideal for manufacturing, automotive, and construction applications requiring dependable flat head fasteners that combine performance with regulatory compliance.

Specification Summary & Compliance

Manufactured to precise inch system dimensions with Class 2A thread fit tolerance ensuring consistent threading performance. Complies with ASME B18.6.3 mechanical standards for dimensional accuracy and mechanical properties. Meets RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) environmental regulations for restricted substance compliance. Features right-hand thread direction with UNC coarse thread spacing and fully threaded configuration per industrial specifications.