Sandvik Coromant 5857575 Threading Insert 8 Tpi Un

Product Description

The SANDVIK COROMANT 5857575 is a laydown threading insert from the CoroThread 266 series, designed for right-hand external UN thread cutting at 8 threads per inch (TPI). Constructed from solid carbide with a PVD-applied TiCrAlN/TiN coating, this insert delivers wear resistance and coating adhesion suited to threading operations on a range of workpiece materials. The 60-degree included angle conforms to standard UN thread geometry. With a 3/8-inch inscribed circle and 5/32-inch thickness, it fits standard CoroThread 266 toolholders. Machinists and CNC operators install this insert in turning centers and threading lathes for external thread production.

This insert is intended for external UN threading applications in production machining environments, including job shops and manufacturing facilities running CNC turning equipment. The F chipbreaker geometry suits single-point threading passes on external diameters. It is sized for insert style 266 with a 16 size code, making it compatible with CoroThread 266 system toolholders designed for that insert size. Applications typically include threading of fastener blanks, fittings, and other components requiring UN-standard external threads.

Key Features

• Solid carbide substrate with PVD TiCrAlN/TiN coating for extended tool life in threading applications
• Right-hand external UN thread profile at 8 TPI with 60-degree included angle
• CoroThread 266 series insert, style 266, size code 16
• F chipbreaker for controlled chip formation during threading passes
• 3/8-inch (9.53 mm) inscribed circle, 5/32-inch (3.97 mm) thickness
• Manufacturer grade 1135 matched to the TiCrAlN/TiN PVD coating system

Compatibility

Designed for use with CoroThread 266 series toolholders accepting insert style 266, size code 16, with a 0.1732-inch (4.40 mm) hole diameter. Refer to the SANDVIK COROMANT CoroThread 266 toolholder catalog to confirm holder compatibility before installation.

Installation Notes

Installation is performed by a machinist or CNC tooling technician. Power down and lock out the machine spindle before seating or removing the insert. Use the correct torque driver specified by the toolholder manufacturer for the clamping screw — do not over-torque, as carbide inserts are brittle and can crack under excessive clamping force. Inspect the insert seat and clamping surfaces for chips or debris before seating the new insert.