Sandvik Coromant 7860793 Turning Insert DCMT21.51-PF 4425

Product Description

The SANDVIK COROMANT 7860793 is a DCMT-style solid carbide turning insert designed for precision external turning operations on CNC lathes and turning centers. Identified by ISO code DCMT 07 02 04-PF 4425, this insert features a 55-degree diamond shape with a 7-degree relief angle (clearance code C) and a 0.40 mm (0.0156 inch) corner radius. The grade 4425 substrate is CVD-coated with a TiCN, Al2O3, and TiN multilayer stack, delivering wear resistance and thermal stability at the cutting edge. The PF chip breaker geometry is optimized for finishing passes. A licensed machinist or CNC operator installs this insert as part of routine tooling maintenance on turning tool assemblies.

This insert is suited for finish to semi-finish turning of steel (ISO material code P) and cast iron (ISO material code K) in both residential shop and industrial production environments. The CoroTurn 107 series designation indicates compatibility with Sandvik Coromant CoroTurn 107 toolholders that accept DCMT-style inserts with clamp or screw holding methods. With 2 cutting edges per insert, it supports economical edge indexing during production runs. The neutral hand orientation makes it adaptable to both right-hand and left-hand turning configurations depending on the toolholder used.

Key Features

• Grade 4425 solid carbide substrate with CVD-applied TiCN, Al2O3, and TiN multilayer coating for extended tool life on steel and cast iron
• 55-degree diamond insert shape (shape code D) with 7-degree relief angle provides clearance during turning passes
• PF chip breaker geometry engineered for finishing operations
• 1/4 inch (6.35 mm) inscribed circle with 0.40 mm corner radius for fine surface finish requirements
• 2 indexable cutting edges per insert for cost-effective use
• Neutral hand orientation compatible with clamp and screw toolholder holding methods

Compatibility

Designed for use in SANDVIK COROMANT CoroTurn 107 series toolholders accepting DCMT-style inserts with a 1/4 inch inscribed circle, tolerance code M, and clearance code C. Compatible toolholders use clamp or screw holding methods. ISO code DCMT 07 02 04-PF 4425 can be used to cross-reference equivalent toolholder seat specifications.

Installation Notes

Insert indexing and replacement should be performed by a qualified machinist with the machine powered down, spindle locked, and coolant flow stopped before accessing the toolholder. Use the appropriate Torx or hex key specified by the toolholder manufacturer to secure the clamp or screw — do not overtighten, as this can fracture the insert or damage the seat. Inspect the toolholder pocket and seat for chips or debris before seating the new insert. Follow the machine tool manufacturer and toolholder manufacturer guidelines for proper torque and seating procedures.