S-90390A121 5/16"-18 x 1" Tapping Screws

Key Features & Benefits at a Glance

• Superior corrosion resistance with black-phosphate steel coating, extending service life in demanding environments
• Effortless installation through thread cutting design that eliminates pre-tapping in aluminum, brass, cast iron, and sheet metal
• Maximum torque transfer with T40 Torx drive system, reducing cam-out and tool slippage during high-torque applications
• Flush surface finishing enabled by 82° countersink angle and standard flat head profile for clean, professional installations
• Enhanced holding power through fully threaded design that maximizes engagement across the entire 1" length
• Reliable thread engagement with UNC coarse threads providing strong, vibration-resistant connections in various materials
• Optimized material compatibility with recommended L drill bit (0.29") for precise hole preparation in specified metals

Professional Applications & Engineering Value

These 5/16-18 T40 flat head tapping screws deliver exceptional engineering value by solving critical installation challenges in metal fabrication and assembly. The black-phosphate steel construction provides essential corrosion protection for industrial environments, while the thread cutting technology (Type F) eliminates the need for separate tapping operations, significantly reducing assembly time and labor costs. The T40 Torx drive ensures reliable torque transmission without stripping, making these screws ideal for high-volume production lines where consistent performance is paramount. Engineered specifically for aluminum, brass, cast iron, and sheet metal applications, these fasteners maintain structural integrity under vibration and load stress, providing durable connections in automotive, machinery, and construction assemblies where UNC coarse threads offer superior pull-out resistance.

Specification Summary & Compliance

Manufactured to precise dimensional standards with Class 2A thread tolerances and UNC coarse thread profile (5/16"-18). Features standard 82° countersink angle and fully threaded 1" length design. The black-phosphate surface treatment provides corrosion resistance while maintaining compliance with industrial fastener specifications. These thread cutting screws (Type F) are engineered for reliable performance in specified metal substrates when used with recommended L drill bit (0.29" diameter).