Iscar 5901939 Threading Insert 11.5 Tpi Npt IC908 Carbide

Product Description

The ISCAR 5901939 is a laydown-style solid carbide threading insert designed for cutting internal NPT threads at 11.5 threads per inch (TPI). Finished with a PVD-applied TiAlN coating and manufactured in the IC908 grade, this insert delivers consistent thread form on a wide range of workpiece materials including steels, stainless alloys, cast irons, non-ferrous metals, and high-temperature alloys. The 3/8 inch (0.375 inches) inscribed circle and 0.143 inch thickness conform to the 16IR insert style designation. A right-hand cutting orientation is standard. Machinists and toolroom technicians installing tapered pipe threads on CNC lathes or manual threading setups will find this insert suitable for production and maintenance applications alike.

This insert is intended for internal NPT tapered pipe thread applications requiring a 11.5 TPI form. It is part of the ISCARTHREAD series and suits threading operations on materials spanning the P, M, K, N, H, and S material grade classifications per ISO 13399 designations. Typical use cases include machining pipe fittings, valve bodies, hydraulic manifolds, and fluid-system components where NPT thread integrity is critical. The insert seats in compatible 16IR toolholders used on CNC turning centers and manual lathes equipped for laydown insert geometry.

Key Features

• IC908 solid carbide grade with PVD TiAlN coating for wear resistance and thermal stability
• 11.5 TPI right-hand internal NPT thread form for tapered pipe thread machining
• 3/8 inch inscribed circle, 16IR insert style — seats in standard 16IR toolholders
• 0.143 inch insert thickness for consistent seating and repeatable depth of cut
• Universal primary workpiece material compatibility across H, K, M, N, P, and S material codes
• Compliant with ISO 13399 cutting tool data representation standards

Compatibility

Designed for use in 16IR-style laydown threading toolholders compatible with the ISCARTHREAD series. Insert geometry and thread form suit internal NPT threading operations at 11.5 TPI on compatible CNC turning and manual lathe setups.

Installation Notes

This insert is installed and replaced by a machinist or toolroom technician. Power down and lock out the machine spindle before seating or removing the insert. Ensure the toolholder pocket and clamping screw are clean and free of chips before installation to maintain accurate insert positioning. Verify thread form and pitch with a calibrated NPT thread gauge after the first pass to confirm correct seating before committing to a full threading cycle.