Sandvik Coromant 5857579 Threading Insert 18 Tpi Un

Product Description

The SANDVIK COROMANT 5857579 is a solid carbide laydown threading insert designed for external UN thread cutting at 18 threads per inch. Part of the CoroThread 266 series, it carries a PVD-applied TiCrAlN/TiN coating that provides wear resistance and thermal stability during threading operations. The insert features a right-hand cutting orientation, a 60-degree included angle, and an F chipbreaker geometry. It is intended for use by machinists and CNC turning specialists working on threaded external profiles in production or job-shop environments.

This insert is suited for external UN threading applications on CNC lathes and turning centers. The 266RG-16UN01F180E designation in the 1135 grade indicates a coated carbide formulation optimized for threading steel and similar ferrous workpiece materials. The single-tooth profile and laydown-style seating make it appropriate for precision thread form control in both high-volume production runs and lower-volume precision work.

Key Features

• Solid carbide substrate with PVD TiCrAlN/TiN coating for extended tool life
• 18 TPI external UN thread profile with 60-degree included angle
• Right-hand cutting orientation, laydown insert style
• F chipbreaker geometry for controlled chip formation during threading
• CoroThread 266 series toolholder compatibility
• 3/8-inch (9.53 mm) inscribed circle; 5/32-inch (3.97 mm) thickness

Compatibility

Designed for use with CoroThread 266 series toolholders accepting size 16 laydown threading inserts. Specific toolholder compatibility should be confirmed against SANDVIK COROMANT CoroThread 266 system documentation using insert style code 266 and insert size code 16.

Installation Notes

Threading inserts should be installed and indexed by a qualified machinist with the machine spindle fully stopped and the toolholder secured in the turret. Use the appropriate torx or clamping screw torque driver specified by the toolholder system - do not over-torque the clamping screw. Confirm insert seating is flush and free of chips or debris before resuming cutting operations. Follow shop safety procedures and machine manufacturer guidelines when changing inserts on CNC turning equipment.