Sandvik Coromant 5781993 Laydown Threading Insert Npt 8 Tpi

Product Description

The SANDVIK COROMANT 5781993 is a solid carbide laydown threading insert from the CoroThread 266 series, designed for cutting internal NPT threads at 8 threads per inch. It carries a dual-layer PVD coating of TiCrAlN and TiAlN, which provides thermal resistance and wear protection during threading operations on a range of workpiece materials. The insert features a right-hand cutting orientation, a 60-degree included angle standard for NPT profiles, and a single-tooth-per-side configuration for controlled thread form accuracy. With a 3/8 inch inscribed circle and 5/32 inch thickness, it seats in compatible CoroThread 266 toolholders. This insert is installed by machinists and CNC tool setup technicians working in precision threading applications.

This insert is suited for internal NPT thread production on CNC lathes and turning centers in both production shop and job shop environments. The NPT thread standard makes it applicable to pipe fitting and fluid-system component machining where tapered thread sealing is required. The CoroThread 266 insert style and 16 size code designate specific toolholder compatibility. The A chipbreaker geometry is intended for controlled chip formation during single-point threading passes on internal bores.

Key Features

• Solid carbide substrate with PVD-applied TiCrAlN and TiAlN dual coating for extended tool life
• Right-hand cutting orientation for standard internal NPT threading
• 8 TPI at 60-degree included angle — correct geometry for NPT tapered pipe thread profile
• CoroThread 266 series insert style 266RL, size code 16, with A chipbreaker
• 3/8 inch (9.53 mm) inscribed circle and 5/32 inch (3.97 mm) thickness for precise toolholder fit
• Single tooth per side for dedicated thread-form control on each pass

Compatibility

Designed for use in SANDVIK COROMANT CoroThread 266 series toolholders that accept the 266RL-16 insert style. Confirm toolholder bore and clamping method match the 16 size code and laydown seating geometry before installation.

Installation Notes

Installation is performed by a qualified machinist or CNC tool setup technician. Power down and lock out the machine spindle before seating or removing the insert. Use the correct torque wrench and clamping screw specified by the toolholder manufacturer — do not overtighten or substitute fasteners. Inspect the insert pocket for debris or damage before seating the new insert, and verify thread-form accuracy with a thread gauge after the first pass.