Tungaloy 6859784 Threading Insert Npt Carbide AH725

Product Description

The TUNGALOY 6859784 is a solid carbide laydown threading insert designed for external NPT thread cutting on CNC lathes and turning centers. Part of the TAC TungThread series, it carries the AH725 grade with a PVD-applied TiAlN coating for wear resistance across a broad range of workpiece materials. The insert features a 60-degree included angle and a right-hand cutting orientation, conforming to ISO standards. With a 3/8-inch inscribed circle and a thickness of 0.02 inches (0.5 mm), it fits toolholders compatible with the 16ER insert style. Licensed machinists and toolroom technicians install this insert on threading toolholders for pipe thread production.

The 6859784 is suited for cutting 27 threads per inch external NPT pipe threads on materials spanning steel, cast iron, stainless steel, nonferrous metals, and heat-resistant alloys. The AH725 grade is rated for universal workpiece material groups including H, K, M, N, P, and S classifications. It is appropriate for both production threading and maintenance repair operations where NPT pipe thread forms are required on external workpieces.

Key Features

• Right-hand external NPT threading at 27 threads per inch
• AH725 solid carbide grade with PVD TiAlN coating for extended tool life
• 60-degree included angle matches NPT thread form geometry
• 3/8-inch inscribed circle, 16ER insert style for standard toolholder compatibility
• Universal material rating covering H, K, M, N, P, and S workpiece groups
• TAC TungThread series, manufactured to ISO standards

Compatibility

Designed for use in 16ER-style threading toolholders accepting a 3/8-inch inscribed circle laydown insert. Suitable for external NPT pipe thread applications across the TAC TungThread toolholder series.

Installation Notes

Installation is performed by qualified machinists or toolroom technicians. Power down and lock out the machine spindle before seating or replacing the insert. Ensure the toolholder pocket and clamping surfaces are clean and free of chips before torquing the clamping screw. Verify thread form and pitch against the NPT specification before committing to a full threading pass.