Sandvik Coromant 5757989 Threading Insert 8 Tpi Api Round

Product Description

The SANDVIK COROMANT 5757989 is a laydown threading insert from the CoroThread 266 series, designed for external API Round thread cutting applications. It is machined from solid carbide and finished with a dual PVD coating of TiCrAlN and TiAlN for wear resistance at elevated cutting temperatures. The insert produces right-hand external threads at 8 threads per inch, with a 60-degree included angle and a 3/8 inch inscribed circle (9.53 mm). At 0.1563 inches thick (3.97 mm), it seats into compatible CoroThread 266 toolholders. This insert is installed by machinists and tool-and-die professionals working in oilfield, pipe fitting, and heavy industrial threading operations.

This insert is used for external API Round threading on pipe, couplings, and related oilfield tubular components. It is suited to CNC turning centers and manual lathes equipped with CoroThread 266 compatible toolholders. The chipbreaker designation A and single-tooth cutting profile make it appropriate for threading passes on round-thread API connections commonly encountered in oil country tubular goods (OCTG) manufacturing and repair. The insert grade 1125 is formulated for threading under stable cutting conditions where PVD-coated carbide provides edge integrity and surface finish control.

Key Features

• Solid carbide substrate with dual PVD coating: TiCrAlN and TiAlN for heat and wear resistance
• API Round external thread profile at 8 TPI with 60-degree included angle
• Right-hand cutting orientation for standard external threading operations
• 3/8 inch (9.53 mm) inscribed circle with 0.1732 inch (4.40 mm) mounting hole diameter
• CoroThread 266 series — designed for repeatable indexing and consistent thread form
• Manufacturer grade 1125 with PVD coating process for dimensional stability at the cutting edge

Compatibility

Designed for use with CoroThread 266 series toolholders that accept insert size code 16. Confirmed manufacturer catalog number is 266RG-16RD01A080E 1125.

Installation Notes

This insert is installed by a qualified machinist. Power down and lock out the machine spindle before indexing or replacing any insert. Seat the insert fully in the pocket and verify torque on the clamping screw per the toolholder manufacturer specifications — do not overtighten. Inspect the thread form on a test pass before committing to a full production run, particularly when switching between insert indexes.