Sandvik Coromant 7860865 Turning Insert CCMT21.51-UM 4425

Product Description

The SANDVIK COROMANT 7860865 is a solid carbide turning insert in the CCMT21.51-UM 4425 designation, part of the CoroTurn 107 series. It features a CVD-applied multilayer coating of TiCN, Al2O3, and TiN, engineered to extend tool life and maintain cutting edge integrity at elevated machining temperatures. The insert has an 80-degree diamond shape with a neutral hand orientation, a 0.2500-inch inscribed circle, and a 0.40 mm corner radius. Two cutting edges are available per insert. This style is installed by machinists and CNC operators on lathes and turning centers performing external turning operations on steel and cast iron workpieces.

The CCMT21.51-UM 4425 insert is suited for external turning applications in both roughing and finishing passes on steel (ISO material group P) and cast iron (ISO material group K). The UM chip breaker geometry is optimized for light-to-medium cutting depths where controlled chip formation is critical. It is a single-piece solid carbide insert retained by clamp or screw holding methods. Typical installations involve CNC turning centers and manual lathes in production or job-shop environments. The ISO code for this insert is CCMT 06 02 04-UM 4425.

Key Features

• CVD multilayer coating: TiCN, Al2O3, and TiN for wear resistance and thermal stability
• 80-degree diamond insert shape with neutral hand orientation
• 0.40 mm corner radius for controlled surface finish on steel and cast iron
• UM chip breaker geometry for effective chip control in light-to-medium cuts
• Compatible with clamp and screw holding methods
• Two usable cutting edges per insert for cost-effective tooling

Compatibility

Designed as a CoroTurn 107 series replacement insert for toolholders accepting CCMT 06 02 geometry inserts. Primary workpiece material is steel (ISO P); secondary workpiece material is cast iron (ISO K).

Installation Notes

Installation is performed by a qualified machinist or CNC setup technician. The machine spindle must be stopped and all motion fully halted before indexing or replacing the insert. Use the appropriate torx or hex key to the toolholder manufacturer's specified clamping method when securing via screw or clamp. Inspect the insert pocket and seating surface for chips or debris before seating the new insert to ensure proper contact and edge alignment.