There are many manufacturers of ATC tools for CNC machine tools. The following are some internationally renowned ATC tool manufacturers:

1. Sandvik Coromant: As a world-renowned supplier of cutting tools and machining solutions, Sandvik Coromant offers a variety of cutting tools and tool systems, including ATC tools.

2. Kennametal: Kennametal is a well-known global supplier of cutting tools and cutting tool systems, providing high-performance ATC tools for various CNC machine tool applications.

3. Iscar: Iscar is a world-renowned supplier of metal cutting tools, providing a variety of high-quality ATC tools to meet different processing needs.

4. Walter: Walter is a manufacturer focusing on high-precision cutting tools, providing various ATC tools, including milling cutters, drills, threading tools, etc.

5. Seco Tools: As a world-renowned metal cutting solution provider, Seco Tools offers a comprehensive ATC tool product line covering various applications such as turning, milling, drilling, etc.

In addition to the above manufacturers, there are many other ATC tool manufacturers, such as OSG, Kyocera, Mitsubishi, etc. The choice of which brand of ATC tool to choose should be based on specific processing requirements, tool performance requirements and budget and other factors. You can consult professional suppliers or dealers and make a choice based on actual conditions.