Electrodes

Tungsten electrodes are identified by their colour-coded tip. Gold WL15 and blue WL20 are lanthanated general-purpose electrodes that work on both DC and AC – they are now the most common choice for steel and aluminium. Grey WC20 is ceriated and strikes easily at low currents. Green WP is pure tungsten and intended for AC.

The most common diameters are 1.6 mm and 2.4 mm. As a rule of thumb, 1.6 mm is good for about 150 amps and 2.4 mm for about 250 amps.

The grinding angle of the electrode tip affects the arc: a sharp point concentrates the arc for thin materials, while a blunter point can handle higher current.