S-90390A124 5/16"-18 x 1 3/4" Tapping Screws

Key Features & Benefits at a Glance

• Superior corrosion resistance with black-phosphate steel construction for extended service life in harsh industrial environments
• Enhanced torque transmission through T40 Torx drive design, preventing cam-out and ensuring secure installation
• Efficient thread cutting capability with Type F tapping design creates precise mating threads in aluminum, brass, and cast iron without pre-tapping
• Optimal flush mounting with standard flat head profile and 82° countersink angle for smooth surface finishes
• Reliable coarse thread engagement with UNC 5/16"-18 threading provides strong holding power in sheet metal and soft materials
• Full-length threading ensures maximum grip along the entire 1 3/4" length for superior fastening security
• Comprehensive material compatibility specifically engineered for aluminum, brass, cast iron, and sheet metal applications

Professional Applications & Engineering Value

These thread cutting tapping screws solve critical fastening challenges in metal fabrication and assembly operations. The black-phosphate steel construction provides essential corrosion protection where exposure to moisture and industrial atmospheres would compromise ordinary fasteners. The T40 Torx drive system delivers exceptional torque transfer, eliminating the stripping issues common with Phillips or slotted drives in high-torque applications. With their Type F thread cutting design and coarse UNC threading, these screws form perfect mating threads in aluminum components, brass fittings, cast iron housings, and sheet metal assemblies without requiring pre-tapped holes. The 82° countersink angle and flat head profile ensure flush mounting in precision applications where protruding fasteners would interfere with mechanical operation or aesthetic requirements.

Specification Summary & Compliance

Manufactured to precise dimensional standards with UNC coarse thread (5/16"-18) and Class 2A thread tolerances for consistent performance. Features fully threaded design with blunt tip configuration and standard flat head profile. Engineered for use with L drill bit (0.29" diameter) for optimal thread engagement. Complies with industry-standard specifications for thread cutting tapping screws and meets relevant material and performance standards for industrial fastening applications.