Sandvik Coromant 7860739 Turning Insert CNMM644-PR 4425

Product Description

The SANDVIK COROMANT 7860739 is a CNMM-style turning insert designed for high-productivity metal cutting on CNC lathes and turning centers. Part of the T-Max P series, this insert carries manufacturer grade 4425 and features a multilayer CVD coating of TiCN, Al2O3, and TiN applied over a solid carbide substrate. The coating sequence delivers thermal resistance, wear protection, and reduced built-up edge when cutting at elevated speeds. The PR chip breaker geometry is engineered for steel turning applications where reliable chip control and consistent tool life are the primary requirements. The neutral hand orientation makes it suitable for both external and face turning operations.

This insert is intended for turning operations on steel and cast iron workpieces, covering both roughing and semi-finishing passes where the PR geometry and 4425 grade perform best. It fits standard CNMM toolholders with clamp or screw clamping. The 80-degree diamond shape provides two cutting edges per insert, reducing cost per edge on production runs. Typical users include machinists and CNC operators in job shops, production facilities, and maintenance shops working on shafts, flanges, and similar turned components.

Key Features

• T-Max P series, grade 4425 carbide with CVD multilayer TiCN, Al2O3, TiN coating for extended tool life on steel
• PR chip breaker geometry optimized for steel primary workpiece material (ISO code P) and cast iron secondary (ISO code K)
• 80-degree diamond insert shape (CNMM) with neutral hand for versatile external and face turning
• 1/16 inch (0.0625 inch) corner radius for a balance of edge strength and surface finish
• Two cutting edges per insert for efficient cost-per-edge on production runs
• Clamp and screw compatible holding method for use in standard CNMM-style toolholders

Compatibility

Designed to fit standard CNMM-style turning toolholders that accept a 19.05 mm inscribed circle insert. ISO code CNMM 19 06 16-PR 4425. Compatible with clamp and screw clamping systems. Primary workpiece material: steel (ISO P). Secondary workpiece material: cast iron (ISO K).

Installation Notes

Installation should be performed by a qualified machinist or CNC tooling technician with the machine in a full stop and lockout state before indexing or replacing inserts. Use the appropriate torx or hex key as specified by the toolholder manufacturer when tightening the clamping screw. Inspect the insert pocket and seating surface for chips or debris before seating the insert to ensure proper contact and prevent premature edge failure. Do not exceed the toolholder manufacturer recommended depth of cut or feed rate for this insert size and grade.