Sandvik Coromant 5781922 Threading Insert 24 Tpi Un

Product Description

The SANDVIK COROMANT 5781922 is a laydown threading insert designed for external UN thread cutting on CNC lathes and turning centers. It carries manufacturer part number 266RG-16UN01A240M and belongs to the CoroThread 266 series. The insert is manufactured from solid carbide and coated with a dual PVD finish of TiAlN and TiCrAlN for wear resistance at elevated cutting temperatures. It cuts right-hand external UN threads at 24 threads per inch (TPI) with a 60-degree included angle. The inscribed circle measures 3/8 inches (9.53 mm) and the insert thickness is 5/32 inches (3.97 mm). Machinists and CNC operators install this insert in compatible CoroThread 266 toolholders for precision threading operations.

This insert is suited for external threading of UN-standard fastener forms on steel, alloy steel, and similar workpiece materials in production and job-shop environments. The A-style chipbreaker geometry supports controlled chip evacuation during single-point threading passes. It is appropriate for use on manual and CNC lathes where a laydown insert orientation is required. The CoroThread 266 series is widely used in high-volume threading applications where consistent thread form and insert longevity are priorities. One tooth per side is active per pass, making setup and indexing straightforward for the operator.

Key Features

• Solid carbide substrate with dual PVD coating: TiAlN and TiCrAlN for heat and wear resistance
• Cuts right-hand external UN threads at 24 TPI with a 60-degree included angle
• A-style chipbreaker for controlled chip flow during threading passes
• Inscribed circle of 3/8 inches; insert thickness of 5/32 inches
• Hole diameter of 0.1732 inches (4.40 mm) for secure toolholder mounting
• Part of the CoroThread 266 series; insert size code 16

Compatibility

Designed as a replacement-style insert for CoroThread 266 series toolholders that accept a size-16 laydown threading insert in right-hand external UN thread configurations.

Installation Notes

Installation is performed by a qualified machinist or CNC technician. The machine spindle must be stopped and the toolholder must be fully secured in the turret before indexing or replacing the insert. Use the appropriate torx or hex key specified for the CoroThread 266 clamping screw torque to avoid damaging the carbide seat. Inspect the insert pocket and seating surface for chips or debris before seating the new insert.