I don't have a CNC machine to talk about its performance in this environment. However, I bought them to make some parts with a rotary tool on a plastic backing and they worked fine. Can follow a line and has a fairly clean edge that only needed minimal smoothing. Note that in this case you will have to stop every now and then to clean the nozzle as it will lose its cutting power if the surface becomes clogged with material. All in all a good buy, now they live next to my rotary tool.