Tool numbering and selection (T word) in CNC Programming

Introduction

Tool numbering and selection lets the CNC machine know which tool to use for cutting. It tells the machine to pick the right tool from the tool holder.

When starting a CNC program to choose the first tool.

When changing tools during a machining process.

When setting up the machine to use a specific tool for a job.

When programming multiple operations that need different tools.

Syntax

CNC Programming

T[number] M6

T[number] tells the machine which tool to select.

M6 is the command to change the tool.

Examples

Selects tool number 1 and changes to it.

CNC Programming

T1 M6

Selects tool number 5 and changes to it.

CNC Programming

T5 M6

Selects tool number 12 and changes to it.

CNC Programming

T12 M6

Sample Program

This simple CNC program selects tool number 3 using T3 M6. Then it sets positioning and moves to the start point.

CNC Programming

O1000 (Sample program)
T3 M6 (Select tool 3 and change)
G90 G54 (Absolute positioning, work offset)
G0 X0 Y0 (Move to start position)
M30 (End program)

Important Notes

Always use M6 after T[number] to tell the machine to change tools.

Tool numbers must match the tools loaded in the machine's tool holder.

Some machines may require a pause or confirmation after tool change.

Summary

Tool numbering tells the machine which tool to use.

M6 command changes the tool to the selected number.

Use T[number] M6 to select and change tools in CNC programs.