S-90390A113 1/4"-20 x 3/4" Tapping Screws

Key Features & Benefits at a Glance

• Superior corrosion resistance with black-phosphate steel coating, extending service life in demanding industrial environments
• Enhanced torque transmission from the T30 Torx drive, reducing cam-out and tool wear for reliable installations
• Self-tapping efficiency with Type F thread cutting design, eliminating the need for pre-tapped holes in materials like aluminum and cast iron
• Secure flush mounting thanks to the standard flat head profile and 82° countersink angle, providing a smooth finished surface
• Optimized thread engagement with UNC coarse 1/4"-20 threading and full-length threads, ensuring maximum pull-out resistance
• Broad material compatibility for use in aluminum, brass, cast iron, and sheet metal applications without specialized tooling
• Precision sizing with 3/4" length and 0.25" diameter, manufactured to inch system standards for consistent performance

Professional Applications & Engineering Value

These thread cutting screws deliver exceptional value in metalworking and assembly operations where durability and efficiency are critical. The black-phosphate steel construction provides reliable corrosion protection in humid or outdoor settings, while the Type F tapping screw design with UNC coarse threads creates precise mating threads in ductile materials like aluminum, brass, and cast iron. The T30 Torx drive eliminates stripping issues common with Phillips drives, reducing assembly time and tool replacement costs. With full threading and a blunt tip, these self-tapping fasteners maintain alignment during installation and distribute stress evenly across the joint—ideal for sheet metal assemblies, machinery frames, and automotive components where vibration resistance is essential.

Specification Summary & Compliance

Manufactured to inch system standards with 1/4"-20 UNC coarse threads and standard Class 2A thread tolerances for consistent fit. Features a flat head profile with 82° countersink angle and fully threaded shank. Compatible with No. 1 drill bit (0.228" diameter) for proper hole preparation. The black-phosphate surface treatment meets industrial corrosion resistance requirements, while material composition complies with RoHS and REACH environmental standards for safe use in various applications.