S-90390A552 1/4"-20 x 2 1/2" Tapping Screws

Key Features & Benefits at a Glance

• Superior corrosion resistance with black phosphate coating for extended service life in demanding industrial environments
• Enhanced torque transmission through T30 Torx drive design, reducing cam-out and tool wear during installation
• Self-tapping efficiency with Type F thread cutting design that eliminates the need for pre-tapped holes in multiple materials
• Optimal flush installation with standard flat head profile and 82° countersink angle for clean, professional finishes
• Versatile material compatibility specifically engineered for aluminum, brass, cast iron, and sheet metal applications
• Reliable coarse threading with 1/4"-20 UNC fully threaded design providing maximum holding power
• Precision installation guidance with specified No. 1 drill bit (0.228") requirement for proper hole preparation

Professional Applications & Engineering Value

These black phosphate steel tapping screws deliver exceptional performance in metal fabrication and assembly operations. The Type F thread cutting design creates precise mating threads in aluminum, brass, cast iron, and sheet metal without pre-tapping, significantly reducing installation time and labor costs. The T30 Torx drive system provides superior torque transfer compared to traditional drive types, minimizing fastener damage and ensuring consistent clamping force in high-vibration applications. The 82° countersink angle combined with the standard flat head profile ensures flush mounting in precisely prepared holes, making these 1/4-20 UNC coarse thread screws ideal for manufacturing equipment, structural assemblies, and metal enclosures where reliability and professional appearance are critical.

Specification Summary & Compliance

Manufactured to precise dimensional standards with UNC coarse threading (1/4"-20) and Class 2A thread tolerances for consistent performance. Features right-hand thread direction and fully threaded design for maximum engagement. The black phosphate surface treatment provides corrosion protection while maintaining dimensional integrity. These thread cutting screws comply with industry standards for Type F tapping screws and are compatible with standard No. 1 drill bit (0.228") preparation and 82° countersink angles for proper installation in various metal substrates.