What is an Automatic Tool Changer? Types of automatic tool changers (ATC)

An automatic tool changer is an accessory that is part of those milling machines equipped with a numerical control and which allows that the change of tools in the milling head is carried out in a programmed way and without the intervention of an operator. The automatic tool changer is directed at making the operator´s work easier by changing the tools automatically, with no requirement for operator intervention. Controlled by the CNC, the main function of this automatic tool changer (ATC) is therefore to optimise machining times and to facilitate work on complicated parts with machining processes that require the use of a large variety of tools, thereby improving productivity.

Automatic tool changer types for CNC milling machines

Automatic tool changer types in used CORREA milling machines


With regard to the second-hand CNC milling machines retrofitted by NC Service, there are various automatic tool changers types.

Automatic tool changer (ATC)

The automatic tool changer (ATC) is either located on one of the milling machine columns or on a separate floor-standing holder. In turn, there are a number of types:

Depending on the movement of the gripper arm making the tooling changeover, the automatic tool changer can be:

  • Curved travel: the tool magazine is perpendicular to the head and the tool gripper arm travels in a curve in order to change over the tool on the milling head.
  • Straight travel: the magazine and head are in the same plane, therefore the arm has a straight line of travel in order to perform the changeover.

 And, depending on the position of the magazine, the automatic tool changer can be either horizontal or vertical.


Static tool changer (AES)

The static tool changer (AES) can be positioned either over the table or moved towards the table in order to change over the tools. In turn, the static tool changer can be either horizontal or vertical, and motor-driven or not.


Thanks to the different types of automatic tool changers, this accessory can be perfectly adapted to the machining needs of each and every customer.

In our process to refurbished CNC second-hand milling machines, we also adapt to these requirements, either by rebuilding the tool changers already fitted on the second-hand milling machine or installing a new ATC, based on the requirements of each particular customer. An inspection, repair and/or replacement of the electrical, hydraulic and mechanical components, as well as a regulation of the mechanical stops and a new parameterization of the tool clamping are carried out in most of the cases. Also, in some occasions in which the milling machines did not have this accessory, it is possible to include the installation of a newly manufactured ATC during the retrofitting process.

In this video you can see a tool exchange test during the repair of an ATC with clamp for the refurbishment process of the Anayak HVM5000 milling machine.


Always aiming to seek the optimal machining solution for each of our customers. Please feel free to enquire!