What is M-Code: Definition, Functions & Types
CNC machining has become the backbone of the manufacturing industry, and it is dependent on CNC machines. CNC machines are used in many applications, and when it comes to learning about their programming, M-code is very critical.
The guide below tells what is M-code, how it works, and much more, so let's read.
What is M-Code in CNC Programming?
M-code is a short form for miscellaneous code, which is an important CNC machining aspect. G-code directs the machine's movements, and M-code instructs the machine in non-movement functions.
M-code looks into processes like turning the spindle off during machining, changing the tool, coolant control, etc.
Origin of M-Code Programming
M-code programming was invented in the 20th century when manufacturing was transitioning from labor to automated processes.
At that time, Frank L. Stulen and John T. Parsons developed number controls. CNC machines were developed with M-code and G-code. The first one was invented at MIT under joint efforts and funding from the US Air Force.
What is the Importance of M-code?
The significance of M-code cannot be denied, and some of these considerations that make it important are as follows:
- M-code helps streamline the machining process and provides instructions for machines to function. Automated actions like changes in tools and coolant control are carried out by these codes, minimizing human intervention.
- M-code offers enhanced flexibility to CNC machines. It can perform a wide range of tasks in a versatile way, such as stopping the spindle or activating the coolant.
- It integrates with G-code when M-code doesn't work alone. G-code and M-code together create a programming language that can cleverly handle the different CNC machining aspects.
How Does an M-code Work?
M-code integrates with CNC programming to perform specific tasks, it sets the commands which control machine functions. It works in the following way:
- M-code programming uses certain codes which instruct machines to perform certain actions. These codes have a specific format and sequence that are followed by the machines.
- Once the code is programmed, the machine works according to that code. The controllers interpret codes and conduct the corresponding actions.
What is the Structure of an M-code?
M-code structure has a letter M with a numerical value. It represents the specific instruction.
For example:
M00: It stops the program
M03: Moves the spindle clockwise
M06: Changes the tool
Common Types of M Codes
The common types of M codes are discussed below.
M00 Program stop: M00 stops the program and halts the machine so that the operator can make any adjustments if required.
M01 Optional program stop: M01 is used for operational program stops and allows the operator to make any changes if required in programming.
M02: M02 represents the ending of the program and refers to the completion of the operation.
M03 Spindle on clockwise: It is used in milling operations as it rotates the spindle in the clockwise direction.
M04 Spindle on counterclockwise: M04 rotates the spindle in a counterclockwise direction.
M05 Spindle off: M05 steps the spindle for safety and transitional purposes during operation.
M06 Tool change: M06 is used for changing the tool.
M08 Coolant on: It activates the coolant to manage the temperatura.
M09 Coolant off: It stops the coolant when the program ends.
M30 Program end, return to start: M30 represents the ending of programming and taking the machine back to the start point.
Other M-codes: Some other types of M-codes are M10 clamp-on, M98 subprogram call, M19 spindle orientation, and M07 coolant on mist.
| M-Code | Descrizione |
| M00 | It stops the program |
| M01 | It is for the operational stopping of the program |
| M02 | It ends the program |
| M03 | It starts the spindle |
| M05 | It stops the spindle |
| M06 | It changes the tool automatically |
| M07 | It applies mist coolant |
| M08 | It applies flood coolant |
| M09 | It turns the coolant off |
| M30 | It ends the program and resets the machine |
Examples of Standard M-Code Simulators
M-code simulators help visualize CNC programs before their execution. Some of the M-code simulators used by CNC programmers are as follows:
- CNC simulator Pro
- CAMotics
- G-wizard Editor
- Mastercam Simulator
- NC viewer
How to Read M Codes？
M-code command readings need some familiarity with the codes and their functions.
M-code has a letter and a number that represents the function of the machine. These are written within the CNC machine's program so that the machine controllers can read them and translate them into actions.
What Machines Use M-code?
M-code is used in CNC machines to manage different functions. The common types of CNC machines that use M-code are the following:
- CNC lathes
- Water jet cutters
- Grinders
- Plasma cutters
- Milling machines
- Electric discharge machines.
How to Program a CNC Machine with M-Code Commands
In order to program CNC machines with M-code commands, you need to understand the M-codes properly. This program is done manually as well as with the CAD and CAM software.
To program CNC machines with M-code commands, you can follow the steps below.
- Every M-code has a specific control function, so make sure to understand that properly.
- Select a compatible programming language that your machine can understand. Write the program using M-codes to control the machining functions.
- Set up the CNC machine, install the right tools, and make sure the workpiece is held properly.
- Now load and run the program and check if the CNC machine is executing the commands or not.
- Monitor the entire process properly, and once the product is read, inspect it, ensuring that the part meets the dimensional requirements.
Who Needs to Know M-code?
The M-code must be known by the following people:
- Machine operators
- CNC programmers
- Machine Technicians
- Manufacturing technicians
- Tool designers
- CNC machines sales team
Differences Between M-code and G-code
M-code deals with the process of controlling the functions of machines that are not movement-related, like turning the machine on or off or applying coolant. At the same time, G-code controls the geometric movements of the machine like feed rate, positioning and speed.
They create a set of instructions for the CNC machines when combined together, allowing them to machine the components precisely.
Considerations in M-code Programming
In M-code programming, some of the considerations are as follows:
- It is important to understand the specific M-codes for the CNC machine you are using.
- You must ensure that appropriate machine functions and tooling paths are controlled to avoid damage and collision.
- Make sure to check the machine to assess its optimal performance.
Conclusione
M-code plays a critical role in CNC machining processes, and understanding it is also very important to ensure that you achieve highly precise and accurate components.
So, contact us at DEK, and we will provide you with high-quality and precise components. Our team is well-equipped with M-code programming for CNC machines.
