CNMG inserts, also known as CNMG tool inserts, are cutting inserts used in turning operations on lathes and turning centers. These inserts are part of the ISO standard for tooling, specifically ISO 1832, which defines the geometry and specifications of turning inserts.

CNMG inserts feature a rhombic shape with four cutting edges. They have a neutral rake angle, which means the cutting edge is perpendicular to the workpiece surface. The medium chip breaker design is suitable for general-purpose turning applications, providing a balance between chip control and cutting performance.

The ground hone of CNMG inserts ensures a sharp cutting edge, which enhances the cutting efficiency and surface finish of the workpiece. The inserts are made from a variety of cutting tool materials, such as carbide, cermet, or cubic boron nitride (CBN), depending on the specific machining requirements.

CNMG inserts are commonly used for turning operations in both roughing and finishing applications. They are suitable for a wide range of materials, including steels, stainless steels, cast irons, non-ferrous metals, and exotic alloys. The inserts are clamped into tool holders or tool posts on the lathe or turning center, allowing them to perform precise cutting operations with high efficiency.

It’s important to note that while CNMG inserts are widely used, there are also other types of inserts available in the ISO standard, each designed for specific machining applications and workpiece materials.