S-90585A074 1/2"-13 x 1 3/8" ASME B18.3 Stainless Steel Hex Drive Flat Head Screws

Key Features & Benefits at a Glance

• Superior corrosion resistance with 316 Stainless Steel construction and passivated finish, ideal for harsh environments and extended service life
• Exceptional mechanical strength offering 70,000 psi tensile strength and Rockwell B55 hardness for reliable performance in demanding applications
• Precision thread engagement with Class 3A fit and UNC coarse threading, ensuring secure fastening and vibration resistance
• Optimized flush mounting featuring a standard 82° countersink angle and flat head design for a smooth, finished surface
• Efficient installation and removal with a 5/16" hex drive, providing positive torque transfer and reducing tool slippage
• Full threading along the 1 3/8" length for maximum grip and adjustability across the entire fastener
• Compliance with major industry standards including ASME B18.3, RoHS 3, and REACH, ensuring quality and environmental safety

Professional Applications & Engineering Value

This 1/2"-13 UNC Flat Head Screw is engineered to address critical challenges in industrial and marine settings where corrosion resistance and structural integrity are paramount. The 316 Stainless Steel material, enhanced by a passivated finish, provides excellent protection against chlorides and acidic conditions, reducing maintenance costs and failure risks. The fully threaded design with coarse UNC threads and Class 3A fit ensures high clamping force and resistance to loosening under dynamic loads. Commonly used in machinery, structural assemblies, and offshore equipment, these screws deliver reliable performance where high tensile strength (70,000 psi) and precise flat head seating are required for flush, aerodynamic, or safety-critical surfaces.

Specification Summary & Compliance

Manufactured to precise dimensional tolerances, including head diameter (0.938") and Class 3A thread fit for consistent performance. Threads conform to UNC 1/2"-13 coarse spacing with full threading along the 1 3/8" length. The screw meets ASME B18.3 specifications for inch-series fasteners and is compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) regulations, ensuring adherence to environmental and safety standards for industrial use.