Sandvik Coromant 5757691 Threading Insert 16 Tpi Un

Product Description

The SANDVIK COROMANT 5757691 is a laydown threading insert designed for cutting external UN threads on a lathe or CNC turning center. Part of the CoroThread 266 series, this solid carbide insert carries a dual PVD coating of TiCrAlN and TiAlN under manufacturer grade 1125, which provides wear resistance and thermal stability during threading operations. It produces a 60-degree included angle at 16 threads per inch and is configured for left-hand thread cutting. The inscribed circle measures 3/8 inches and the insert thickness is 5/32 inches. Typically installed by machinists and CNC operators in precision threading applications.

This insert is suited for external UN thread applications in metalworking environments, including production turning and job-shop threading operations. The left-hand orientation makes it appropriate for reverse-thread workpieces or left-hand spindle configurations. With a single tooth per side and an A-style chipbreaker, it is designed for controlled chip formation during threading passes on ferrous and non-ferrous materials. It fits insert-style toolholders compatible with the CoroThread 266 series using a 0.1732-inch hole diameter.

Key Features

• Solid carbide substrate with PVD-applied TiCrAlN and TiAlN dual coating for extended tool life
• Left-hand, external UN thread configuration at 16 TPI with a 60-degree included angle
• A-style chipbreaker for predictable chip control during threading passes
• 3/8-inch inscribed circle and 5/32-inch thickness for precise insert seating
• CoroThread 266 series insert compatible with corresponding 266-series toolholders
• UNSPSC Code 23291804 for procurement and catalog classification

Compatibility

Designed for use with CoroThread 266 series toolholders accepting a 266-style insert with a 0.1732-inch (4.40 mm) mounting hole. Manufacturer catalog number 266LG-16UN01A160M 1125 may be used for cross-reference with SANDVIK COROMANT tooling systems.

Installation Notes

Installation is performed by machinists or CNC setup technicians. Power down and lock out the machine spindle before changing inserts. Use the appropriate SANDVIK COROMANT torx or insert-clamping key to seat the insert fully and evenly in the pocket. Verify insert orientation and thread hand before resuming cutting operations.