Sandvik Coromant 8021253 Turning Insert Cnmg 12 04 16-MF 4415

Product Description

The SANDVIK COROMANT 8021253 is a CNMG-style indexable turning insert carrying ISO designation CNMG 12 04 16-MF 4415. It is a CVD-coated carbide insert with a TiCN, Al2O3, and TiN multilayer coating stack engineered to deliver high wear resistance through moderate wear resistance and toughness on steel workpieces. The insert features an 80-degree diamond (rhombic) shape, a neutral hand orientation, a 0.5-inch inscribed circle, and a 0.0625-inch corner radius. It seats in standard CNMG toolholders using a clamp or screw holding method and is intended for roughing and medium machining operations on steel and some cast-iron applications.

This insert is suited for CNC turning centers and manual lathes in production and job-shop environments where steel components require aggressive material removal or mid-range finishing passes. The 4415 grade sits in the ISO P primary workpiece material classification, making it appropriate for carbon steels, alloy steels, and other ferrous materials. The CNMG-MF chip breaker geometry supports controlled chip evacuation during both roughing and medium machining passes. Machinists and CNC operators in metalworking and precision machining trades install this insert as a direct indexed replacement within compatible CNMG toolholder systems.

Key Features

• CVD-applied TiCN, Al2O3, and TiN multilayer coating for extended tool life on steel
• 80-degree diamond (rhombic) insert shape provides strong cutting edge geometry for heavy cuts
• Negative side clearance with M-tolerance for reliable, repeatable seating in standard CNMG pockets
• 0.0625-inch corner radius balances edge strength and surface finish across roughing and medium passes
• CNMG-MF chip breaker geometry supports controlled chip flow in roughing and medium machining
• ISO P primary grade classification targets steel; ISO K secondary classification extends use to select cast-iron applications

Compatibility

Designed as an OEM-style indexable replacement for standard CNMG toolholder pockets accepting the CNMG 434 (ANSI) or CNMG 120416 (ISO) insert size with clamp or screw holding.

Installation Notes

Installation is performed by qualified machinists or CNC tooling technicians. Power down and lock out the machine spindle before indexing or replacing inserts. Use the appropriate torx or hex key to the toolholder manufacturer's recommended procedure when tightening the clamp or screw — do not overtighten, as this can fracture the insert or damage the pocket seat. Inspect the toolholder pocket and shim for wear or debris before seating a new insert to ensure proper support and accurate positioning.