# Cutting Speed, Depth And Feed Speed Of Custom CNC Machined Parts

Through CNC machining of customized parts, we often hear the three terms of cutting speed, depth of cut, and feed rate. Cutting parameters include cutting speed, back-cutting amount, and feed rate. For different processing methods, different cutting parameters need to be selected. So today we will separately introduce what the cutting speed, depth of cut and feed rate are.

## What Is The Cutting Speed (Vc)?

What we usually call the cutting speed is generally-(m/min) meters/minute as the calculation unit, and the professional term is expressed by Vc. Cutting speed is also the most important parameter for cutting. The cutting speed is the instantaneous speed of a certain point on the cutting edge of the tool relative to the machined surface in the main movement direction, which provides forced movement for the cutting operation.

### Cutting Speed Formula

vc=( π*dw*n)/1000

vc—-cutting speed (m/min)

dw—-The diameter of the workpiece surface to be processed (mm)

n—-Workpiece rotation speed (r/min).

## What Is The Cutting Depth (ap)?

The width of the metal layer cut from the customized CNC machined part during the CNC machining process refers to the cutting depth. The method of calculating the depth of cut is to use the vertical distance between the uncut surface and the machined surface of a custom CNC machined part, in inches or millimeters (mm).

### Cutting Depth Formula

Under the condition that the rigidity of the process system and the power of the machine tool allow, choose a larger cutting depth as much as possible to reduce the number of feeds. When the accuracy of the workpiece is required to be high, a finishing allowance should be considered, which is generally 0.1 to 0.5 mm.

ap = (dw-dm)/2

ap-the amount of knife to be back (mm)

dw—-The diameter of the workpiece surface to be processed (mm)

dm—-The machined surface diameter of the workpiece (mm)

## What Is The Feed Speed (vf)?

The feed speed v f refers to the instantaneous speed of the selected point on the cutting edge relative to the workpiece feed movement. The feed amount f refers to the relative displacement of the tool and the workpiece in the direction of the feed movement per revolution of the workpiece or tool. According to the feed direction, it is divided into longitudinal feed and transverse feed. The longitudinal feed refers to the feed along the direction of the lathe bed guide, and the transverse feed refers to the direction perpendicular to the lathe bed guide. Feed rate. The feed speed v f refers to the instantaneous speed of the selected point on the cutting edge relative to the workpiece feed movement.

### Feed Speed Formula

vf=f*n

vf—-feed speed (mm/s)

n—-spindle speed (r/s)

f—-feed rate (mm /s)

## Conclusion

With the wide application of CNC machine tools in actual production, CNC programming has become one of the key issues in CNC machining. In the process of compiling the NC program, it is necessary to instantly select the tool and determine the cutting amount under the human-computer interaction state. Therefore, programmers must be familiar with the selection method of the tool and the principle of determining the amount of cutting, so as to ensure the processing quality and processing efficiency of the parts, give full play to the advantages of CNC machine tools, and improve the economic efficiency and production level of the enterprise.