Depth of Cut in Machining: Tout ce qu'il faut savoir

In CNC machining, the depth of cut is very crucial to understand. It is a major parameter in the machining process and impacts the quality of the components.

This article features a detailed insight into the depth of cut in machining and how it is measured. Read the guide below.

What is the Depth of Cut in Machining?

During the machining process, the depth of cut means how deep a tool would go to cut the workpiece. The process of cutting is ideal in cases where the CNC cutter moves with a given depth inside the surface of the workpiece by moving to the left.

Such a depth is known as the depth of cut. The value of the depth of the cut is mostly measured in millimeters and inches, and can range between 0.1 to 1 millimeters.

Why is Depth of Cut Important in Machining?

The depth of cut is a very significant aspect of machining. Along with the wear rate of the tool and the quality of the machined surface, the significance of depth cannot be disregarded.

You can take the example of annealed metals, as they are more susceptible to built-up-edge formation when the process of cutting takes place than cold-worked metals.

Le BUE chip has layers of chips that are collected at the top of the cutting tool. Therefore, this collection impacts the surface finish of the component if the depth is higher.

How to Calculate the Depth of Cut?

The important parameters that are important to consider to calculate the depth of the cut are as follows:

• The type of CNC machining process like milling, turning, drilling, etc
• The capabilities of the machine
• Properties of cutting tool tip
• Type of material
• Required tolerance and surface finish

Depth of Cut for CNC Turning

Le processus de Tournage CNC works by rotating the workpiece and cutting along the length of it. In this case, the depth of the cut and the feed rate can be identical as the distance covered by the cutting tool is measured in mm/min.

The depth of cut, in this case, is calculated using the given formula:

Depth of Cut for CNC Milling

The CNC tool rotates in Fraisage CNC, and the workpiece is fixed on the work table. The depth of the cut, in this case, is based on the diameter of the cutting tool being four times of it, where the diameter is larger.

When the diameter is smaller, the cutting depth is ten times the diameter of the cutter.

How Does the Depth of Cut Influence Other Machining Factors?

The depth of the cut is related to the machining process parameters, which impact the surface quality and properties of the workpiece. Some of the ways the depth of cut influences other machining factors are discussed below:

• The heat on the tool tip impacts the workpiece when thermoplastics are machined, as they have low thermal conductivity.
• The maximum depth, cutting speed, and rake angles need adjustments. So that the temperature can be reduced and chips do not stick to the tool's chip.
• When the depth of the cut is reduced, the curvature of the chips is also reduced, and the chips turn out to be curly.
• If you are using a cutting fluid, it can help reduce the heat, but the chips curl more. It impacts the contact between the chip and the tool.
• A chip breaker can help manage the wear of the tool.

Compare Chip Thickness Value vs. Depth of Cut Value

The difference between the chip thickness and the depth of the cut are two very important considerations.

During the cutting process, let's take “à” as the depth of cut and “tc” as the thickness of the chip. The tool cutter removes the material at an angle of ϕ. The chip thickness, in this case, is more than the depth cut value.

The chip thickness and cutting ratio defines the ratio between the chip thickness and depth of cut, and to calculate it, the following formula can be used:

r= to/tc

In order to calculate the chip thickness and cutting ratio from the shear angle and rake angle, the cooling formula can be used:

ϕ: represents shear angle

a: represents rake angle

The chip compression factor is reciprocal of the value, which indicates the thickness of the chip when compared to the cut depth.

Depth of Cut vs Cutting Forces and Power

When calculating the cut depth, it is important to know the cutting power and forces, which are the essential parameters. These parameters also require considering factors like:

• CNC tools strength so that the desired finish is achieved, and rapid wear and tear is avoided.
• The fixtures and holders used to clamp the workpiece are also considerable as it is important to mitigate distortion during the cutting process.

The speed of the spindle and the force of cutting, when multiplied, give the power.

P= FсV

In the formula above, Fc is the cutting force that is exerted by the tool to cut the material in a direction that is the same as the velocity of the tool. The energy that is required to allow shearing force to cut the surface of the workpiece is Nous.

Moreover, the friction-specific energy is also important to manage the friction between the workpiece surface Uf and the tool.

Ut = Us + Uf

The friction-specific energy and shear-specific energy are associated with the cut depth and can be calculated as follows:

The engineers use these formulas to determine the cut depth for specific machine parameters:

Practical Tips for Choosing The Optimum Depth of Cut in Machining

In order to choose the optimum depth of cut during the process of machining, some of the important tips to consider are as follows:

Properties of Material

The process of CNC machining materials is an important consideration for the depth of the material.

The workpiece material impacts the depth. The way the workpiece is used with the cutting tool is based on the material properties like its toughness, thermal conductivity, and strength. The harder materials make the engineers choose small depths so that tool wear can be avoided.

Machine Operation Type

The different processes of machining have different outcomes. The type of operation must be considered when determining the cut depth. Roughing operations can cater to the larger cut depths and quickly remove the materials, but the surface finishing lacks.

Capability of Machining Tool

The power of the machining tool has an influence on the cutting depth during the machining process. When the machine is rigid and versatile, the higher cutting force can help with a larger cut depth. However, if the machining tool is not very strong, the depth may be smaller.

Characteristics of Cutting Tools

CNC tools have varied characteristics that determine the depth of cut during the machining process. The material it is made of, the coating, and the geometry it has can also create different depths.

Machinists mostly opt for tools that are advanced and have coatings that are high-performance so that the life of the tool is enhanced. It helps to allow aggressive depth and manages the heat distribution and chip formation well.

Start Your Custom Machined Parts Project with DEK

If you want to start a new project for custom machined parts with ideal depths of cuts, you can contact DEK.

We offer to manufacture these components for you with our experienced engineers and advanced cutting tools. We carefully consider the depth of the cut in the component and offer you an optimal component.

Conclusion

The depth of cut in machining needs to be managed very carefully, and factors like surface finish and chip removal also play a role. So, the guide above must have helped you make the right decision regarding the cut of the depth of your CNC machined components.

FAQ

What are the factors on which the cut of depth depends?

The depth of cut depends on the material quantity that is removed, the material from which the tool is made, and the power of the machining tool.

What is the measurement unit of the depth of the cut?

The SI unit used to measure the depth of the cut is millimeters.

What is the ideal depth of cut?

The ideal depth of a cut must range between 0.1 mm to 1 mm.