S-90390A593 5/16"-18 x 2 1/2" Tapping Screws

Key Features & Benefits at a Glance

• Superior thread cutting performance in aluminum, brass, cast iron, and sheet metal for reliable fastening in demanding industrial applications
• Enhanced corrosion resistance with black phosphate steel coating, extending service life in harsh environments
• High-torque capability from T40 Torx drive, reducing cam-out and tool wear for efficient assembly
• Precision alignment and flush mounting with standard flat head profile and 82° countersink angle
• Optimized chip clearance with UNC coarse threads and blunt tip design, preventing clogging in dense materials
• Full-length threading ensures maximum grip and load distribution across the entire fastener length
• Compatible with standard L drill bit (0.29") for quick, accurate pilot hole preparation

Professional Applications & Engineering Value

These 5/16"-18 thread cutting tapping screws are engineered to address common challenges in metal fabrication and assembly. The Type F thread cutting design with UNC coarse threads creates precise mating threads in aluminum, brass, cast iron, and sheet metal without pre-tapping, significantly reducing installation time and labor costs. The black phosphate steel construction provides excellent corrosion protection for outdoor equipment, automotive components, and industrial machinery. The T40 Torx drive system delivers superior torque transmission compared to traditional drives, minimizing strip-outs and ensuring consistent clamping force in high-vibration environments. The 82° countersink angle and flat head profile enable seamless flush mounting in predrilled applications, while the fully threaded shank maximizes pull-out resistance in thick metal sections.

Specification Summary & Compliance

These thread cutting tapping screws feature 5/16"-18 UNC coarse threads with standard Class 2A tolerances for consistent fit. The Type F tapping screw design complies with industry standards for thread forming fasteners. Manufacturing follows quality control protocols for dimensional accuracy, including 0.313" thread diameter, 2-1/2" length, and 0.635" head diameter. The black phosphate surface treatment meets industrial corrosion protection requirements and is RoHS and REACH compliant for environmental safety.