Almost every day I use my plasma torch to cut aluminum and steel for engineering and repair. These consumables are so expensive that I did not hesitate to turn them on and make the necessary cuts. I've read reviews that say they don't last very long, but I've found that if they keep the air dry and the right distance from the metal surface, they last a lot longer. I have had the Lotos LT5000d plasma for three years now. This is my second set of consumables.