Sandvik Coromant 7860851 Turning Insert DNMG432-QM 4425

Product Description

The SANDVIK COROMANT 7860851 is a DNMG432-QM 4425 indexable turning insert designed for external and internal turning operations on CNC lathes and turning centers. Built from solid carbide with a CVD-applied multilayer coating of TiCN, Al2O3, and TiN, this insert delivers wear resistance and thermal protection during continuous and interrupted cuts. The 55-degree diamond shape provides a strong cutting edge with good approach-angle flexibility. With a 0.79 mm (0.0313 inch) corner radius and a neutral hand orientation, it suits a wide range of turning applications. Four cutting edges per insert maximize tool life per unit. Machinists and CNC operators in job shops and production environments are the primary installers.

This insert is engineered primarily for machining steel (ISO material code P) and secondarily for cast iron (ISO material code K). The QM chip breaker geometry is suited to medium to roughing cuts where chip control and edge stability are critical. It fits into standard DNMG-style toolholders using clamp and screw holding methods. The T-Max P series designation indicates compatibility with Sandvik Coromant's T-Max P toolholder family. Typical applications include shaft turning, facing, and profiling on ferrous workpiece materials in both light production and heavy-cycle environments.

Key Features

• CVD multilayer coating: TiCN, Al2O3, and TiN for high wear and heat resistance
• 55-degree diamond insert shape (ISO shape code D) with neutral hand orientation
• 0.79 mm (0.0313 inch) corner radius for balanced edge strength and surface finish
• Four usable cutting edges per insert for extended tool economy
• QM chip breaker geometry optimized for steel and cast iron chip control
• Fits clamp and screw style DNMG toolholders; ISO code DNMG 15 04 08-QM 4425

Compatibility

Designed for use in DNMG-style indexable turning toolholders that accept clamp and screw holding methods. ISO insert code is DNMG 15 04 08-QM 4425. Part of the Sandvik Coromant T-Max P series. Primary workpiece material compatibility is steel; secondary is cast iron.

Installation Notes

Installation is performed by CNC machinists or tool-room technicians during toolholder setup or insert indexing. Power down and lock out the machine spindle before changing inserts. Use the correct torx or hex key specified by the toolholder manufacturer when tightening the clamp screw — do not overtighten, as this can fracture the insert or damage the seat. Inspect the insert pocket and seating surface for chips or debris before seating a new insert.