• ascnc@asianstarcnc.com

A Comprehensive Guide to CNC Turning Codes: Mastering G-Code for Precision Machining

Introducing CNC Turning Codes

CNC (Computer Numerical Control) turning is a widely-used machine tool technology that has revolutionized the machining industry. With the ability to control and automate precise cutting, drilling, and forming operations on a variety of materials, CNC turning ensures increased productivity, accuracy, and flexibility in manufacturing. At the core of CNC turning lies a set of instructions known as CNC codes, primarily comprising G-codes and M-codes. This blog post aims to provide a comprehensive guide to these turning codes, helping you master the programming language of CNC turning to achieve precision machining.

Understanding G-Code and M-Code

G-codes, or preparatory codes, are alphanumeric codes used to specify the type of movement and operation the CNC machine will perform. These codes control functions such as linear interpolation, plane selection, rapid traverse, and many more. M-codes, on the other hand, are auxiliary codes that control various machine functions, such as spindle on/off, coolant on/off, tool changes, and other essential tasks.

Essential G-Codes for CNC Turning

1. G00 - Rapid Traverse\

This G-code commands the machine to move the cutting tool rapidly to a specified position. The rapid traverse ensures minimal time is wasted between cuts.

2. G01 - Linear Interpolation\

G01 allows for linear cutting or movement in a straight line between two specified points. Users must provide feed rate (F) and axis coordinates (X, Y, or Z) alongside this code.

3. G02 - Clockwise Circular Interpolation\

This code commands the machine to make a clockwise circular cut, while considering the specified center point and the endpoint of the arc.

4. G03 - Counterclockwise Circular Interpolation\

Similar to G02, G03 commands a counterclockwise circular cut, with a specified center point and endpoint.

5. G04 - Dwell Time\

G04 pauses the cutting tool at a specified point for a predetermined time (in seconds), allowing for operations like chip clearing and coolant application.

6. G28 - Return to Machine Zero\

This code commands the cutting tool to return to a predefined machine zero (home) position after completing an operation.

7. G90 - Absolute Positioning Mode\

G90 specifies that all coordinates for the subsequent motion commands are given in absolute terms (relative to the machine's origin).

8. G91 - Incremental Positioning Mode\

In contrast to G90, G91 commands the machine to interpret all coordinates in an incremental fashion, relative to the last position of the cutting tool.

Fundamental M-Codes for CNC Turning

1. M00 - Program Stop\

M00 pauses the machine operation, allowing for manual interventions.

2. M01 - Optional Program Stop\

M01 is similar to M00, but it only stops the program if an optional stop switch or setting is enabled on the control panel.

3. M02 - End of Program\

This code indicates the termination of the CNC program.

4. M03 - Spindle Start (Clockwise)\

M03 activates the spindle rotation in a clockwise direction.

5. M04 - Spindle Start (Counter-Clockwise)\

Conversely, M04 commands the spindle to rotate in a counterclockwise direction.

6. M05 - Spindle Stop\

M05 ceases the spindle rotation.

7. M06 - Tool Change\

This code facilitates an automatic tool change procedure.

8. M08 - Coolant On (Flood)\

M08 activates the flood coolant to help control heat and optimize cutting conditions.

9. M09 - Coolant Off\

M09 deactivates the coolant system.

10. M30 - End of Program with Return to Start\

When the program concludes, M30 returns the machine to the starting point and rewinds the program, preparing it for the next run.

Practice Makes Perfect

Mastering G-Code and M-Code takes practice. Beginners should begin by familiarizing themselves with basic codes and gradually progressing to more complex operations and combinations. This guide serves as a foundation to comprehend the essentials of CNC turning codes, but hands-on experience with actual CNC machines and programming software is invaluable. As you gain experience and confidence, your skillset will enable you to achieve precision machining with ease.

cnc turning codes pdf

What is CNC Turning

CNC turning is a process that involves using computer numerical control (CNC) machines to shape and finish various materials, such as metals and plastics, into desired shapes and sizes.
This process is typically used in the manufacturing industry to produce precision parts and components for a wide range of applications, including automotive, automation, aerospace, medical, machinery, and industrial.

CNC Turning service

Asianstar Professional CNC Turning Service

Asianstar CNC turning Service offers precision machining for a wide range of materials, including metals, plastics, and composites. With high level facilities and skillful operators, we can produce high-quality parts with tight tolerances and intricate designs.

Our CNC turning capabilities allow us to produce parts with diameters ranging from 0.5 mm to 480mm and lengths up to 450mm. We offer both single and multi-axis turning, as well as live tooling options for added complexity and accuracy.

We use proven processes and quality control measures to ensure that every part we produce meets our clients' specifications and expectations.

Whether you need a single prototype or high-volume production runs, our CNC turning service can provide the precision and reliability you need to get your project completed on time and on budget.

CNC Turning service

Components Sizes of Asianstar CNC Turning Service

Unit (mm) Min Max
Out Diameter 0.5 480
Inner Diameter (Hole) 0.3 465
Length 1.0 450
Groove Diameter 0.4 above
Thread M1.2 above

Components Tolerance of Asianstar CNC Turning Service

Unit (mm) Tolerance according to sizes
Height Tolerance Diameter Size 0.5 to 3 3 to 6 6 to 30 30 to 120 120 to300 300 to480
Tolerance ±0.003 ±0.010 ±0.020 ±0.030 ±0.035 ±0.040
Length Tolerance Length Size 0.5 to 3 3 to 6 6 to 10 10 to 20 20 to 30 30 above
Tolerance ±0.010 ±0.020 ±0.250 ±0.250 ±0.030 ±0.035

Components shape and position tolerance of Asianstar CNC Turning Service

Tolerance Class followed Tolerance (mm)
Straightness and Flatness Verticality Symmetry
10 10 to 30 30 to 100 100 to 300 300 to 1000 1000 to 3000 to 100 100 to 300 300 to 1000 1000 to 3000 to 100 100 to 300 300 to 1000 1000 to 3000
H ±0.015 ±0.02 ±0.03 ±0.05 ±0.10 ±0.15 ±0.02 ±0.025 ±0.03 ±0.035 ±0.02 ±0.03 ±0.04 ±0.05

Capability of Asianstar CNC Turning Service

Type of Turning Machine Diameter Size (mm) Length Size (mm) Productivity (PCS/Month)
Auto Turning Machine Simple Turning Machine Multi Turning Machine Pin Turning Machine Min 0.5 Max 480 Min 1.0 Max 450 200’000/Item


Multiple Machining Processes

Multiple Machining Processes

Asianstar has various machining processes to support different types of components from client, we can choose the best suitable manufacturing solution to carry result in perfect performance and cheap cost

Flexible Custom Service

Flexible Custom Service

With skillful machining technologies, Asianstar is flexible to support clients on different materials and different structures of the components, we also flexible on the components quantities and even assembly

Create Designing for Clients

Create Designing for Clients

Not only producing according to clients drawings, Asianstar also propose the better designing to clients, supporting clients to buildup improved designing or even new generation components

Standard Procedures

Standard Procedures

Asianstar production, as experienced by many years, is strictly following internal Standard Operating Procedures, to make sure the production schedule is smooth and plans are well carried out well without accidents

Standard Procedures

Standard Procedures

Asianstar strictly controlling product quality by system. We start QC controlling from production plan once setting up, to production process by monitoring QC checking and until the final Inspection before packing

Fast Lead-Time Delivery

Fast Lead-Time Delivery

Asianstar strictly control the production processes, teams keep the plan moving ahead according to the procedures, we have internal time management schedule which mostly bring earlier lead-time of delivery

Asianstar: Professional CNC Machining Supplier

From year of 2005, Asianstar Company establish the CNC Machining Factory in Guangdong Province, China.
We mostly provide CNC Turning, Milling, Drilling, Grinding, and Multi Machining processes service on various materials.
With the Belief of becoming a key supplier in the supply-chain of Precision Components, we strictly control our product quality, keep high precision on our components production, buildup the whole-process QC System and submit the satisfaction for every order.
By long term development, we have buildup partnership with world-wide clients, supporting our partners in Designing, Optimizing, Producing and Testing on each type of components.


CNC Turning Service

CNC Turning Service

Our CNC Turning Service provides different sizes of roll shape work-pieces, the diameter range is from 0.5mm to 480mm, reaching tolerance +/-0.003mm.

CNC Milling Service

CNC Milling Service

Our milling machines and CNC centers are able to produce complicated structure part, five-axis devices produce multi-sides at one-time jag which bring high precision result

Sheet Metal Fabrication

Sheet Metal Fabrication

Our Sheet Metal Fabrication provides slicing, punching, bending, welding, painting and assembling for set products, unique tooling for each project to raise production efficiency

Aluminum Extrusion

Aluminum Extrusion

Our Aluminum Extrusion brings clients various shapes of aluminum parts, high efficiency for mass quantity, our precision extrusion mold control tolerance within 0.01mm

Forging Service

Forging Service

For some steel serious products, we apply Forging Service to make out their outer shape and them use CNC devices to start drilling, forming, rolling, cutting, etc.

Finishing Service

Finishing Service

Our Surface Finishing Service uses chemical or electro post-treatments after machining tasks are finished, normally includes Oxide, Anodizing, Passivation, E-Plating, Painting,etc.


  • Q1.Do you support ODM/OEM?

    Yes, we support ODM/OEM, we provide custom-made service for clients or even support clients on designing or improving

  • Q2.Do You Have Stock
  • Q3.What Is Your Production Capacity?
  • Q4.Where Is Your Factory?
  • Q5.Can You Provide Samples?
  • Q6.How About Your After-sales Service?
Get The Best Quotes Now