During the process of cutting, a common question that one encounters is when to change the consumables. There is no simple answer for this and changing consumable depends on several factors.
Factors Affecting Consumable Life
The length of the cut, the thickness of metal that is being cut, if you’re using a machine to cut or cutting by hand, etc., all these factors affect consumable life.
Another key factor that affects the consumables life is the kind of cutting you are doing. If you pierce from the middle of the plate, there is more stress on the consumables rather than when you start the pierce from the side. Also, using a continuous pilot arc for cutting causes the consumables to wear out quickly compared to cutting in normal mode.
Some other factors affecting consumable life include pierce height, the distance between torch-to-work (in the case you are cutting or gouging with consumables that are unshielded), air quality as having too much moisture, oil or other contaminants in the air can affect the consumable life.
While these are some of the factors to consider, there are no real “hard and fast” rules. Typically, a set of consumables will last around 2-3 hours when cutting by hand and around 3-5 hours when cutting by machine. This time is usually the actual “arc on” time, where the plasma is flowing through the plasma torch.
Another consideration to keep in mind is that usually, the electrode is the consumable that will wear out first when you are machine cutting, while it is the nozzle that wears out while cutting by hand. Usually, operators assume that both the electrode, as well as the nozzle, require replacement at the same time, which is not always the case. You can find more information about the proper cutting techniques in the manual that comes along with your cutting system or alternatively, you can also download a copy of the instruction manual from the manufacturer’s website.
Once you understand the factors that impact the consumable life of your plasma cutting system and the general rules to follow, by which you can gauge the life of the consumables, one last important factor to consider is the kind of plasma torch you are using and the consumable required for the particular torch. Newer and more modern types of torches and consumable technologies deliver better performance and life compared to the older technologies.