Sandvik Coromant 5857616 Threading Insert 12 Tpi Un Carbide

Product Description

The SANDVIK COROMANT 5857616 is a solid carbide laydown threading insert from the CoroThread 266 series, designed for internal UN threading applications. This insert carries manufacturer grade 1135 with a PVD-applied TiCrAlN/TiN coating that provides wear resistance and extended tool life in demanding threading operations. It cuts right-hand internal UN threads at 12 threads per inch (TPI) with a 60-degree included angle. Machining professionals and toolroom technicians use this insert for precision thread-cutting on CNC lathes and turning centers where consistent thread form and surface quality are required.

This insert is suited for internal threading on turned components across job shop, production machining, and maintenance repair operations (MRO) environments. The CoroThread 266 series is engineered for stable, vibration-free threading in a range of materials. The F chipbreaker geometry supports chip control during internal thread passes. The insert fits standard CoroThread 266 toolholders designed for the 16-size insert with a 3/8-inch inscribed circle.

Key Features

• Solid carbide substrate with PVD TiCrAlN/TiN coating for wear and heat resistance
• Right-hand internal UN thread profile at 12 TPI with 60-degree included angle
• CoroThread 266 series insert style 266, size code 16
• F chipbreaker geometry for effective chip control on internal threading passes
• 3/8-inch (9.53 mm) inscribed circle; 5/32-inch (3.97 mm) thickness
• 0.1732-inch (4.40 mm) hole diameter for secure toolholder mounting

Compatibility

Designed for use in CoroThread 266 toolholders accepting a 16-size laydown threading insert with a 3/8-inch inscribed circle and right-hand internal UN thread geometry. Verify toolholder insert seat specification before installation.

Installation Notes

Installation should be performed by a qualified machinist or toolroom technician with the machine powered down and the spindle locked before changing inserts. Use the correct torx or hex key to the toolholder manufacturer's specified procedure when seating the insert. Inspect the insert seat and clamping components for wear or debris before fitting a new insert. Do not exceed the cutting parameters specified in the SANDVIK COROMANT CoroThread 266 application guide for this grade and coating.