Description

The SECO 03274178 is a solid carbide triangular turning insert in the TNMG432-M5 series, designed for precision metal cutting on CNC lathes and turning centers. Grade TM2501 uses a CVD-applied Duratomic multilayer coating of TiCN, Al2O3, and Cr to deliver wear resistance and thermal stability under demanding cutting conditions. The insert features a 60-degree included angle, a 0.5 inch inscribed circle, and a 0.0315 inch corner radius with a chamfered and honed cutting edge. Primary target material is stainless steel, with steel as the secondary workpiece material. The M5 chip breaker geometry and negative rake angle make this insert well suited for medium-to-finishing turning passes where consistent chip control matters.

This insert is appropriate for general CNC turning applications in both job shop and production environments handling stainless steel and alloy steel components. It supports back turning, boring, facing, and standard OD turning operations. The neutral hand orientation and clamp, pin, or lever-lock holding methods make it compatible with a wide range of standard TNMG-style toolholders. Material grade designations M25, M30, and M35 indicate suitability for moderate to moderately heavy cutting depths, up to a maximum depth of cut of 0.789 inches.

Key Features

CVD Duratomic coating with TiCN, Al2O3, and Cr layers for thermal and abrasion resistance
60-degree triangle insert shape with 6 available cutting edges
M5 chip breaker geometry optimized for stainless steel and steel workpieces
Negative rake angle with chamfered and honed cutting edge for stable, controlled cuts
Compatible with clamp, pin, and lever-lock toolholder holding methods
Multi-use geometry supports turning, boring, facing, and back turning in a single insert

Compatibility

Designed to fit standard TNMG-style toolholders accepting a 1/2 inch inscribed circle triangular insert. ISO code TNMG220408-M5 and industry standard number TNMG432-M5 govern toolholder matching. Conforms to ANSI and ISO insert standards.

Installation Notes

Installation should be performed by a qualified machinist or CNC tooling technician. Power down and lock out the machine spindle before seating or indexing the insert. Verify the toolholder pocket and clamp components are clean and undamaged before installing; debris under the insert seat affects cutting geometry and surface finish. Do not exceed the recommended depth of cut for the selected material grade, and index or replace the insert at the first sign of edge wear to avoid workpiece damage.