Seco 03273909 Turning Insert CNMG433-MF4 TM2501 Carbide

Product Description

The SECO 03273909 is a CNMG433-MF4 indexable turning insert designed for precision metal-cutting operations on CNC lathes and turning centers. Manufactured from solid carbide with a CVD-applied Duratomic multilayer coating of TiCN, Al2O3, and Cr, it delivers hardness and thermal resistance suited to interrupted and continuous cuts. The insert features an 80-degree diamond shape, a 0.5-inch inscribed circle, and a 3/64-inch (0.0472 inch) corner radius. With four usable cutting edges, the MF4 chip breaker geometry, and a chamfered-and-honed cutting edge style, this insert balances edge strength with chip control across a range of feed and depth conditions. It is installed by machinists and CNC operators in production and job-shop environments.

This insert is rated for primary use on stainless steel (ISO material code M, grades M25, M30, M35) and secondary use on steel (ISO material code P). It supports turning, facing, and boring operations and can be held with clamp, pin, or lever-lock toolholding systems. The negative rake angle and N clearance code suit heavy-duty roughing and semi-finishing passes. The ISO designation is CNMG120412-MF4, and it meets both ANSI and ISO insert standards.

Key Features

• CVD Duratomic coating (TiCN, Al2O3, Cr) for heat and wear resistance on stainless and steel
• MF4 chip breaker geometry engineered for controlled chip formation in stainless steel turning
• Four cutting edges per insert for extended tool life per unit cost
• Compatible with clamp, pin, and lever-lock toolholding systems
• Chamfered and honed cutting edge for improved edge toughness
• Negative rake, N clearance — suitable for roughing through semi-finishing passes

Compatibility

Designed as an OEM-style indexable replacement for CNMG433-MF4 style turning insert seats. ISO equivalent designation is CNMG120412-MF4. Fits standard CNMG-series toolholders accepting clamp, pin, or lever-lock retention. Verify toolholder bore diameter against the insert hole diameter of 0.2028 inches before installation.

Installation Notes

Installation is performed by a machinist or CNC operator with the spindle fully stopped and the machine locked out per shop safety procedures. Use the correct torque wrench or clamping screw driver specified by the toolholder manufacturer — do not overtighten the clamping screw. Inspect the insert seat and shim for wear or debris before seating the new insert, as a contaminated seat will cause premature edge failure. Index or replace the insert when cutting forces or surface finish degrade, not after catastrophic edge fracture.