Choosing Turning Inserts for Roughing and Finishing

Home › Industry News › Choosing Turning Inserts for Roughing and Finishing

Turning is a Sumitomo Inserts critical process in metalworking, where the shape and dimensions of a workpiece are refined using a lathe. The choice of turning inserts plays a pivotal role in determining the quality, efficiency, and cost-effectiveness of Kennametal Inserts the turning operation. Whether it's roughing or finishing, selecting the right insert is essential. This article will guide you through the factors to consider when choosing turning inserts for both roughing and finishing operations.

Understanding the Basics

Turning inserts are replaceable cutting edges that are mounted on a tool holder. They come in various shapes, sizes, and materials, tailored to specific cutting applications. Inserts are designed to provide a longer tool life and reduce downtime for tool changes.

Roughing Inserts

Roughing inserts are used for the initial removal of material during the roughing process. These inserts are typically made from hard materials like high-speed steel (HSS) or carbide, which can withstand high temperatures and aggressive cutting conditions. When choosing roughing inserts, consider the following factors:

Insert Geometry: The geometry of the insert affects chip formation, cutting forces, and tool life. Choose an insert with the right geometry for the type of material and cutting conditions.

Insert Material: High-speed steel (HSS) is a common choice for its cost-effectiveness and versatility, but carbide inserts offer superior hardness and wear resistance for more demanding applications.

Insert Size and Shape: The size and shape of the insert should match the tool holder and the workpiece's dimensions. Larger inserts may provide better chip evacuation but may require more power.

Finishing Inserts

Finishing inserts are used to achieve a high degree of accuracy and surface finish in the final stage of turning. These inserts are generally made from materials like carbide, cermet, or diamond, which provide excellent wear resistance and precision. When selecting finishing inserts, keep these points in mind:

Insert Geometry: Finishing inserts require a different geometry to achieve the desired surface finish. They often have a smaller rake angle and a more pointed tip for a smoother cut.

Insert Material: Carbide is the most common material for finishing inserts due to its high wear resistance and sharp cutting edges. Diamond-tipped inserts are used for very hard materials and achieving an exceptionally smooth finish.

Insert Size and Shape: Smaller finishing inserts are generally used for more precise cuts and better surface finishes. The shape should be compatible with the tool holder and the workpiece's features.

Additional Considerations

Beyond the basic factors mentioned above, there are several other considerations when choosing turning inserts:

Coating: Coatings such as TiN (titanium nitride) or AlCrN (aluminum oxide) can improve wear resistance and reduce friction, leading to longer tool life.

Insert Mounting: The method of mounting the insert on the tool holder should be considered, as it affects the stability and performance of the tool.

Toolholder Compatibility: Ensure that the insert is compatible with the toolholder in terms of size, shape, and mounting system.

In conclusion, selecting the right turning inserts for roughing and finishing operations requires a thorough understanding of the material being worked, the desired surface finish, and the cutting conditions. By considering factors such as insert geometry, material, size, and coating, you can optimize your turning process for efficiency and cost-effectiveness.

Choosing Turning Inserts for Roughing and Finishing