Millwright Level 1 Practice Exam

Which type of electrode is commonly used in the CAC-A process?

1. Mild steel

2. Tungsten

3. Copper-coated

4. Carbon-graphite

The correct answer is: Carbon-graphite

In the Carbon Arc Cutting (CAC-A) process, the commonly used electrode is carbon-graphite. This type of electrode is advantageous because it is specifically designed to produce a stable arc with good thermal properties. The carbon content allows for the efficient cutting of metals, as it can withstand high temperatures and carry a significant amount of current. Carbon-graphite electrodes are essential in CAC-A because they create a high-temperature arc that melts the workpiece material, enabling precise cuts. The ability of carbon to generate an effective arc and its thermal conductivity makes it ideal for this application. While other types of electrodes, such as mild steel or tungsten, are utilized in different welding and cutting processes, they do not provide the same benefits as carbon-graphite in the context of the CAC-A process. Copper-coated electrodes, while good for other applications, serve a different purpose and are not optimal for the cutting characteristics needed in CAC-A.