Sandvik Coromant 6868256 Turning Insert DCMT32.51-KM 3225

Product Description

The SANDVIK COROMANT 6868256 is a solid carbide turning insert designed for external and internal turning operations on cast iron workpieces. Carrying the ANSI code DCMT32.51 and ISO code DCMT11T304, it belongs to the CoroTurn 107 series. The insert features a CVD-applied multilayer coating of TiCN, Al2O3, and TiN, which delivers high wear resistance across a range of cutting conditions from roughing through medium machining. The 55-degree diamond (rhombic) shape provides a sharp, positive cutting geometry with a 7-degree relief angle and a neutral hand orientation. The KM chip breaker geometry controls chip flow effectively during interrupted and continuous cast iron cutting.

This insert is suited for CNC turning centers and manual lathes running cast iron components in both roughing and medium machining applications. The CoroTurn 107 series is optimized for screw-on insert holding, making it compatible with corresponding SANDVIK COROMANT tool holders designed for DCMT geometry. The grade 3225 substrate is positioned within the cast iron (K) category, offering a balance of high wear resistance to high toughness. Typical users include CNC machinists and tool-and-die professionals working with gray iron, ductile iron, and similar K-category materials in production environments.

Key Features

• CVD multilayer coating: TiCN, Al2O3, and TiN for extended tool life on cast iron
• 55-degree diamond insert shape with positive side clearance for reduced cutting forces
• KM chip breaker geometry rated for roughing and medium machining operations
• Grade 3225 carbide substrate: cast iron K-category, high wear resistance to high toughness range
• Screw-on insert holding method for secure, repeatable seating in compatible tool holders
• Two cutting edges per insert, neutral hand orientation

Compatibility

Designed for use with SANDVIK COROMANT CoroTurn 107 series tool holders accepting DCMT geometry inserts with screw-on clamping. Intended for cast iron (K-category) primary workpiece material applications.

Installation Notes

Installation should be performed by a qualified machinist following machine tool lockout procedures before indexing or replacing inserts. Use the appropriate Torx or hex key specified for the CoroTurn 107 clamping screw — do not overtighten the screw by hand estimation. Ensure the insert pocket and seating surface are clean and free of chips before seating the insert. Verify correct insert orientation for neutral hand before resuming machine operation.