WL20 Tungsten Electrodes WT20, WP, WC10, WC15, WC20, WL20, WY20 Diameter 0.8 ~ 12.0 mm ISO 9001:2000SGS WL20 tungsten electrode is the ... the same time offers the welder easier arc starting capabilities and a more stable arc. Generally used for DC electrode negative ... or straight polarity applications such as carbon and stainless steels, nickel alloys and titanium.2) color mark: WT20 (red)3) ...