Sandvik Coromant 7860744 DNMG442-PR 4425 Turning Insert

Product Description

The SANDVIK COROMANT 7860744 is a DNMG442-PR 4425 turning insert designed for external and internal turning operations on CNC lathes and turning centers. The insert features a 55-degree diamond shape with a neutral hand orientation and a 0.79 mm (0.0313 inch) corner radius, making it well suited for medium to finishing passes. The 4425 grade substrate is solid carbide with a CVD-applied multilayer coating of TiCN, Al2O3, and TiN, delivering wear resistance and thermal stability across a range of cutting conditions. The insert is held via clamp or screw and carries a tolerance code of M with a clearance code of N. Licensed machinists and CNC operators install and index this insert during scheduled tooling changes.

This insert is engineered primarily for steel (ISO material code P) with a secondary application in cast iron (ISO material code K). It belongs to the T-Max P series, which is positioned for general-purpose turning in production environments. Typical use cases include roughing to semi-finishing passes on steel workpieces where consistent tool life and chip control are priorities. The PR chip breaker geometry manages chip evacuation effectively across moderate feed and depth-of-cut ranges. Both job shops and high-volume production facilities running ferrous workpiece materials will find this insert a standard tooling choice.

Key Features

• CVD multilayer coating: TiCN, Al2O3, and TiN for thermal and abrasion resistance
• 55-degree diamond insert shape (code D) with neutral hand orientation
• 0.79 mm corner radius for a balance of edge strength and surface finish
• 4 cutting edges per insert for extended tooling economy
• PR chip breaker geometry optimized for steel and cast iron applications
• Clamp and screw holding method for secure, repeatable seating

Compatibility

Designed as an OEM-style replacement turning insert for toolholders accepting DNMG 15 06 08 geometry inserts within the T-Max P series. ISO code: DNMG 15 06 08-PR 4425.

Installation Notes

Installation is performed by qualified CNC machinists or tooling technicians. Power down and lock out the machine spindle before indexing or replacing inserts. Use the appropriate torx or hex key as specified by the toolholder manufacturer when seating screw-held inserts — do not overtighten, as this can fracture the carbide. Inspect the insert pocket and clamping surfaces for chips or debris before seating a new insert to ensure proper contact and runout.