Sandvik Coromant 8021255 Turning Insert Dnmg 11 04 12-MF 4415

Product Description

The SANDVIK COROMANT 8021255 is a DNMG-style carbide turning insert designed for general-purpose and finishing turning operations on CNC and manual lathes. Manufactured to ISO P series standards under the DNMG-MF designation, this insert features a CVD-applied multilayer coating of TiCN, Al2O3, and TiN, which provides wear resistance, thermal stability, and a low-friction outer surface. The insert has a neutral hand orientation and a D-shaped (55-degree diamond) geometry with an inscribed circle of 0.375 inches and a corner radius of 0.0469 inches. It is held in the toolholder by clamp or screw and is intended for installation by machinists and tool-crib technicians working in metalcutting environments.

This insert is suited for turning applications involving ISO P and ISO K workpiece material groups, covering a range of steels and cast irons in both production and job-shop settings. The DNMG-MF chip breaker geometry is optimized for light to medium finishing cuts where controlled chip formation and surface finish consistency are priorities. Typical applications include external diameter turning, facing, and profiling on medium-duty CNC turning centers.

Key Features

• CVD multilayer coating: TiCN, Al2O3, and TiN for extended tool life in steel and cast iron turning
• D-shape (55-degree diamond) insert with neutral hand orientation for versatile toolholder compatibility
• MF chip breaker geometry designed for light to medium finishing passes with controlled chip evacuation
• Inscribed circle of 0.375 inches with insert thickness of 0.1875 inches for rigid seating
• Corner radius of 0.0469 inches suitable for finishing operations requiring close tolerances
• Clamp or screw holding method compatible with standard DNMG toolholders

Compatibility

Designed as an OEM-style replacement turning insert for standard DNMG toolholders conforming to ISO P series specifications. Verify toolholder seat geometry and clamping style before installation.

Installation Notes

Insert installation and indexing should be performed by a qualified machinist with the machine powered down and the spindle locked. Use the correct torque driver for screw-type clamping to avoid seat damage or insert fracture. Inspect the toolholder pocket and shim for wear or debris before seating a new insert. Follow the cutting tool manufacturer's recommended starting parameters for feed rate and depth of cut when commissioning a new insert grade.