S-90550A105 1/2"-13 x 1" ASME B18.3, ASTM F879, MIL-DTL-18240 Venting Stainless Steel Hex-Drive Flat Head Screws

Key Features & Benefits at a Glance

• Superior corrosion resistance with 18-8 Stainless Steel construction, ensuring long-term durability in harsh environments.
• Exceptional thread engagement and reliability due to Class 3A fit and fully threaded UNC coarse thread design, minimizing the risk of stripping.
• Secure and efficient installation enabled by the 5/16" hex drive, providing high torque transmission and reducing tool slippage.
• Flush and professional finish with a standard 82° countersink angle flat head, ideal for applications requiring a smooth surface.
• Prevents pressure build-up through the integrated 1/8" vent diameter, making it suitable for sealed or pressurized assemblies.
• Broad industrial compliance meeting ASME B18.3, ASTM F879, and MIL-DTL-18240 standards, ensuring consistent quality and performance.
• Environmentally responsible manufacturing with RoHS 3 and REACH compliance, supporting sustainable procurement practices.

Professional Applications & Engineering Value

This 1/2"-13 UNC flat head screw is engineered to address critical challenges in industrial assembly, such as vibration resistance and material degradation. The 18-8 Stainless Steel offers excellent resistance to oxidation and chemical exposure, making it ideal for marine, chemical processing, and outdoor equipment. The fully threaded coarse UNC thread and Class 3A fit provide superior holding power in metals and plastics, reducing loosening under dynamic loads. The vented design is particularly valuable in applications like machinery housings or fluid systems, where pressure equalization is necessary to prevent seal failure. Combined with the hex drive for high-torque installation, this fastener ensures reliable performance in demanding environments, from heavy machinery to structural frameworks.

Specification Summary & Compliance

This screw adheres to precise dimensional standards, including Class 3A thread fit for tight tolerances and UNC coarse threading with a 1/2"-13 size. It is manufactured in compliance with ASME B18.3, ASTM F879, and MIL-DTL-18240 specifications, ensuring consistency and reliability. The product is also RoHS 3 (2015/863/EU) Compliant and REACH (EC 1907/2006) Compliant, meeting environmental and safety regulations for industrial use.