To begin with, they have different colored bands that are used to identify them. However, there are several other important differences to consider when selecting a tungsten. Here some of the various types with the respective characteristics:
EWTh-2: 2% thoriated tungsten. EWTh-2 is color-coded with a red band. It is known for its durability, ability to withstand high currents, and excellent arc starts. It is primarily welded using a negative polarity and direct current. It does not have great characteristics when welding with AC.
EWLa-2: 2% lanthanated tungsten. EWLa-2 is color-coded with a blue band. It is known for its excellent arc starting ability, excellent current carrying ability, and can withstand many arc cycles. It can be welded as the negative electrode using direct current or with alternating current.EWP: Pure tungsten electrode. EWP is color-coded with a green band. It has excellent arc stability. It is almost exclusively used with alternating current. Tungsten emission is more likely with a pure tungsten electrode when compared with other alloyed tungsten electrodes.
EWCe-2: 2% ceriated tungsten. EWCe-2 is currently color-coded with a gray band, although in the past it was color-coded with an orange band. It is quite similar to EWLa-2 in that it has excellent current carrying ability, excellent arc starting ability, and can last through many different arc start and arc termination cycles.