Filler metal is matched to the parent material, not to the machine. Start with the steel grade and the properties the joint has to meet, and only then choose the process. For mild steels S235 and S355 the standard choice is G3Si1 and G4Si1 wire to EN ISO 14341, ER70S-6 in the AWS designation, which at Böhler means the EMK and EML families. For austenitic stainless steels 304 and 304L you take 308L, for 316 and 316L you take 316L, and for joining dissimilar steels 309L.
Quenched and tempered high-strength steels with a yield strength of 700 to 1100 MPa call for wires from the alform family, creep-resistant CrMo steels for DMO, DCMS, CM 2 and CM 9 wires, and P91 and P92 steels for Thermanit MTS consumables.
The second step is the shielding gas. The M21 mixture, that is 82 percent argon with 18 percent CO2, gives a calm spray arc on mild steel. Pure CO2 gives deeper penetration and more spatter. On stainless steel, mixtures with a small addition of CO2 or oxygen are used, on aluminium pure argon, and on heavier sections argon with helium added. The wrong gas can spoil even the best wire.
The third step is diameter and packaging. Solid wires most often come in 0.8, 1.0, 1.2 and 1.6 mm, on S200 and S300 spools and in drums. TIG rods are 1000 mm long and are packed in 5 kg boxes.
Some of the UTP hardfacing consumables changed names in 2025 to the WEARtig, WEARmig and WEARcore lines. We always give both names, the old one and the new one, so that they can be found.