All Categories


Home > BLOG > The importance of passivation treatment for cemented carbide tools

The importance of passivation treatment for cemented carbide tools

June 26,2023

Isn't the  CNC tool  used in the machining center as fast as possible? Why passivation treatment is required? In fact, tool passivation is not what everyone understands literally, but a way to improve the service life of tools.

Improve tool quality through smoothing, polishing, deburring and other processes. This is actually a normal process after the tool is finely ground and before coating.

What is tool passivation?

By deburring, smoothing and polishing the tool, the quality of the tool can be improved and the service life can be extended. After the tool is finely ground and before coating, its name is not unified at home and abroad. It is called "edge passivation", "edge strengthening", "edge honing", "edge preparation" or " ER (Edge Radiusing) processing", etc.

Why carry out tool passivation?

There are different degrees of microscopic notches (that is, tiny chipping and sawing) on the cutting edge of the tool after being sharpened by ordinary grinding wheel or diamond grinding wheel. During the cutting process, the microscopic gap of the tool edge is easy to expand, which accelerates tool wear and damage.

Modern high-speed cutting and automatic machine tools put forward higher requirements for tool performance and stability, especially coated tools must be passivated before coating to ensure the firmness and service life of the coating.

Purpose of tool passivation

The purpose of the edge passivation technology is to solve the defects of the microscopic notch of the edge of the sharpened tool, reduce or eliminate its sharpness, and achieve the purpose of smoothness, sharpness, firmness and durability.

Main effects of tool passivation

Rounding of the cutting edge: remove the burr on the cutting edge and achieve precise and consistent rounding.


Cutting edge burrs lead to tool wear, and the surface of the processed workpiece will become rough. After passivation treatment, the cutting edge becomes very smooth, which greatly reduces chipping and improves the surface finish of the workpiece.

Polishing of cut grooves

Uniform polishing of tool grooves improves surface quality and chip removal performance.



The smoother the groove surface, the better the chip evacuation, allowing higher cutting speeds. At the same time, after the surface quality is improved, the risk of the tool and the processing material being seized is also reduced. And can reduce 40% cutting force, cutting more smoothly.

Coating Polishing

Removes protruding droplets from tool coatings, improves surface finish and increases lubricating oil adsorption.



Some tiny protruding droplets will be produced on the surface of the coated tool, which improves the surface roughness, making the tool prone to generate greater frictional heat during the cutting process and reduce the cutting speed. After passivation polishing, the droplets are removed and many small holes are left, which can absorb more cutting fluid during processing, so that the heat generated during cutting is greatly reduced, and the cutting speed can be greatly improved.

Zhuzhou Lifa Cemented Carbide industrial Co Ltd. specializes in the production of various types of carbide inserts, providing high-quality products and services for domestic and foreign customers. If you have any inquiries, welcome to contact us!