CNC Machining

I. What is CNC processing?

CNC processing is the abbreviation of "Computer Numerical Control Machining". It is a subtractive manufacturing process: through the pre-programmed instructions of a computer, the movement of the machine tool's tools or the workpiece is automatically controlled, and the excess material is precisely removed, ultimately resulting in parts that meet the requirements of the drawings.

In simple terms: CNC processing: Cut off the excess parts from the entire piece of material → Subtractive manufacturing

CNC processing is widely used in metals, plastics, woods, composite materials, etc., and especially holds an irreplaceable position in fields that require high precision, surface quality, and batch consistency (such as molds, aerospace, medical devices), etc.

II. How does CNC processing work?

The entire CNC processing procedure can be divided into four key steps, forming a closed loop from the drawing to the physical object: 

Step 1: Design (CAD)

Engineers use CAD software to create a three-dimensional digital model of the part.

This step determines the final shape, size, and tolerance of the part. 

Step 2: Programming (CAM)

Import the CAD model into the CAM software.

The CAM engineer sets: 

（1）Tool path (where to start cutting and what trajectory to follow) 

（2）Cutting parameters (spindle speed, feed rate, cutting depth) 

（3）Tool selection (end milling cutter, ball nose cutter, drill bit, etc.) 

（4）The software automatically generates G-code (a text instruction set containing coordinates, speeds and commands) that the machine tool can recognize. 

Step 3: Setup and Tool Alignment (Machine Preparation)

The operator fixes the raw material on the CNC machine, installs the required tools, and determines the precise position of the workpiece in the machine through tool alignment. 

Step 4: Automatic processing (execution)

The machine tool controller reads the G codes line by line and sends instructions to the servo motors, the spindle, the cooling system, etc.

The tool and the workpiece move relative to each other along the predetermined trajectory, completing processes such as milling, turning, drilling, tapping, and boring, and finally obtaining the finished product. 

Throughout the entire process, the operators mainly monitored the equipment status and did not need to manually control the cutting actions.

Our successful case

III. Main Types of CNC Machining and Advantages and Disadvantages of CNC Machining

IV. Why must modern mold manufacturing use CNC processing?

Molds have extremely high requirements for precision, hardness and surface quality. Traditional manual processing is no longer able to meet the demands of modern industry. The necessity of CNC processing in the mold industry is reflected in the following aspects: 

1.Extremely high dimensional accuracy

The clearance between mold parts is usually required to be within 0.01 to 0.03mm. CNC processing can directly achieve this, without the need for repeated adjustment and fitting. 

2. Complex three-dimensional cavities

Modern molds feature deep cavities, thin ribs, curved surfaces, and ejection angles, etc. Manual processing is almost impossible to achieve. CNC machining can complete these tasks in one go. 

3. Hard material processing

The hardness of mold steels (such as P20, H13, S136, NAK80) can reach HRC 50-60 after quenching. CNC high-speed milling (HSM) combined with carbide tools can directly process hard materials, reducing the subsequent processes of electrical discharge machining. 

4. Shorten the mold delivery time

With automated processing, unmanned operation, rapid tool and workpiece replacement, the mold manufacturing cycle has been shortened from several weeks to just a few days. 

5. Repeatability

When the mold needs to be repaired or replicated, simply call the original program for reprocessing, ensuring that the dimensions of the new and old inserts are consistent. 

6. Reduce reliance on human labor

High-quality machinists are becoming increasingly hard to find. CNC processing reduces the reliance on manual skills and ensures quality through the equipment.

Part of our CNC processing services: https://youtube.com/shorts/YRBeXB2I-ns