1. The cutting focus is on the workpiece
We define it as negative focal length, which is mainly used for cutting carbon steel plates. Because cutting carbon steel plate requires oxygen assistance. The cutting focus is above the material to ensure a stable oxygen supply and achieve a good cutting section.
2. The cutting focus is inside the workpiece
We define it as positive focal length, mainly used for cutting stainless steel, aluminum, copper and other materials. Since the focal point is inside the material, high pressure gas assistance, nitrogen or compressed air is required.