S-90086A650 5/16"-18 x 3" ASME B18.6.3, SAE J933 Tapping Screws

Key Features & Benefits at a Glance

• Superior material strength and corrosion resistance with zinc-plated steel construction, ensuring long-lasting performance in demanding industrial environments.
• Effortless installation and reduced assembly time thanks to the Type F thread cutting design, which eliminates the need for pre-tapped holes in materials like aluminum and sheet metal.
• Secure, flush-mount fastening with a standard flat head and 82° countersink angle, providing a clean finish and preventing snagging in assembled components.
• Reliable drive engagement and reduced cam-out with the Phillips No. 4 drive, allowing for consistent torque application and minimizing tool slippage during installation.
• Versatile compatibility across multiple materials including aluminum, brass, cast iron, and sheet metal, making these screws ideal for diverse industrial applications.
• Enhanced thread grip and vibration resistance due to the coarse UNC 5/16"-18 thread and fully threaded shank, ensuring a tight, durable hold in various substrates.
• Compliance with industry standards and environmental regulations, meeting ASME B18.6.3 for quality assurance and RoHS 3 for safe, lead-free use in manufacturing.

Professional Applications & Engineering Value

These zinc-plated steel tapping screws are engineered to address common challenges in metalworking and assembly, such as the need for strong, self-tapping fasteners that reduce labor and material costs. The Type F thread cutting design efficiently forms mating threads in ductile materials like aluminum, brass, and cast iron, eliminating the risk of strip-out and ensuring a secure fit without pre-drilled threads. The coarse UNC thread and fully threaded 3" length provide maximum holding power in sheet metal applications, resisting loosening under vibration. With a flat head and 82° countersink, they sit flush for aerodynamic or safety-critical surfaces, while the Phillips drive offers reliable installation in automated or manual settings. Ideal for HVAC, automotive, and machinery assemblies, these screws deliver consistent performance, reducing downtime and enhancing structural integrity.

Specification Summary & Compliance

These screws adhere to ASME B18.6.3 specifications, ensuring precise dimensional accuracy and performance in thread cutting applications. The UNC coarse thread (5/16"-18) follows standardized spacing for reliable engagement, while the zinc-plated steel material provides durability and corrosion resistance. Compliance with RoHS 3 (2015/863/EU) guarantees they are free from hazardous substances, making them suitable for global industrial use. Additional features include a blunt tip for controlled entry, right-hand thread direction, and compatibility with a 0.29" drill bit (size L) for optimal hole preparation, ensuring seamless integration into professional workflows.