S-90390A535 1/4"-20 x 1" Tapping Screws

Key Features & Benefits at a Glance

• Superior thread cutting performance with Type F design ensures clean, secure threads in various materials without pre-tapping, reducing installation time and labor costs.
• Enhanced corrosion resistance from black-phosphate steel coating prolongs screw life in demanding industrial environments, minimizing replacement frequency.
• High-torque T30 Torx drive provides excellent grip and slip resistance during installation, preventing tool cam-out and ensuring consistent fastening.
• Optimized 82° countersink angle allows the flat head to sit flush with surfaces, creating a smooth finish and reducing snag risks in assemblies.
• Full threading along the 1" length maximizes holding power and distributes load evenly, ideal for heavy-duty applications in metals like aluminum and cast iron.
• Coarse UNC 1/4"-20 thread facilitates quick engagement and strong grip in soft materials, improving assembly efficiency and reliability.
• Compatible with standard #1 drill bit (0.228") simplifies hole preparation, ensuring precise fits and reducing the risk of material damage during installation.

Professional Applications & Engineering Value

These 1/4-20 T30 flat head tapping screws are engineered to address common challenges in metalworking and manufacturing, such as thread stripping and inconsistent fastening. The thread cutting Type F design with coarse UNC threads efficiently forms durable threads in materials like aluminum, brass, cast iron, and sheet metal, eliminating the need for separate tapping operations and reducing assembly time. Made from black-phosphate steel, they offer enhanced resistance to rust and wear, ensuring longevity in harsh conditions. The T30 Torx drive enables high-torque application without slippage, while the 82° countersink angle provides a seamless finish. Ideal for industrial machinery, automotive components, and structural assemblies, these screws deliver reliable performance, lower maintenance costs, and improved productivity in right-hand thread applications.

Specification Summary & Compliance

This product adheres to UNC coarse thread standards with a 1/4"-20 thread size and Class 2A tolerance for precise fit. It features a flat head with standard profile, fully threaded shank, and blunt tip for controlled penetration. Manufactured in the inch system, it complies with industry specifications for thread cutting Type F tapping screws. The black-phosphate surface treatment meets common environmental and safety guidelines, supporting durability in diverse industrial settings.