Sandvik Coromant 5757696 Threading Insert 20 Tpi Left Hand Un

Product Description

The SANDVIK COROMANT 5757696 is a laydown threading insert designed for cutting external UN threads in metalworking and machining applications. Part of the CoroThread 266 series, this solid carbide insert carries a dual PVD coating of TiCrAlN and TiAlN for wear resistance and extended tool life. It is engineered for left-hand external threading at 20 threads per inch (TPI) with a 60-degree included angle. The inscribed circle measures 3/8 inches and the insert thickness is 5/32 inches (0.1563 inches). This insert is installed and used by machinists and CNC operators working on threaded component production in precision manufacturing environments.

This insert is suited for external UN thread turning on CNC lathes and manual turning centers in job shop and production machining settings. With a chipbreaker designation of A and a single tooth per side, it is configured for controlled chip flow during threading passes. The insert style is 266 with size code 16, matching the CoroThread 266 toolholder system. It is appropriate for both light and medium-duty threading operations on steel and similar materials where PVD-coated carbide grades are specified.

Key Features

• Solid carbide construction with PVD-applied TiCrAlN and TiAlN dual coating for wear resistance
• Left-hand external UN thread profile at 20 TPI with 60-degree included angle
• Inscribed circle of 3/8 inches (9.53 mm) and insert thickness of 5/32 inches (3.97 mm)
• Chipbreaker style A with one tooth per side for controlled chip formation
• Manufacturer grade 1125 within the CoroThread 266 series
• Hole diameter of 0.1732 inches (4.40 mm) for secure clamping in compatible toolholders

Compatibility

Designed for use with CoroThread 266 series toolholders accepting insert style 266 with size code 16. The manufacturers catalog number for this insert is 266LG-16UN01A200M 1125.

Installation Notes

This insert is installed by qualified machinists or CNC tooling technicians. The machine spindle and all axis motion must be fully stopped and the machine placed in a safe lockout state before changing inserts. Use the appropriate torx or clamping wrench specified for the CoroThread 266 toolholder to seat the insert securely without over-torquing. Inspect the insert seat and clamping components for debris or wear before installation to ensure proper seating and thread quality.