October 31, 2026 · Indumor
Starting values for welding in the flat position with pure argon. Stainless takes somewhat less current than carbon steel, and vertical or overhead a little less again. The cup is given by its number, the bore in sixteenths of an inch. These values are a place to start: fine-tune them on scrap and, when there is a procedure, the WPS rules.
| Material | Thickness | Current (A) | Current type | Tungsten, mm (in) | Rod, mm (in) | Cup no. | Argon, L/min (CFH) |
|---|---|---|---|---|---|---|---|
| Steel or stainless | 1 mm (20 ga) | 30 to 60 | DCEN | 1.0 to 1.6 (0.040 to 1/16) | 1.0 to 1.6 (0.040 to 1/16) | 4 to 5 | 5 to 7 (11 to 15) |
| Steel or stainless | 1.5 to 2 mm (16 to 14 ga) | 60 to 100 | DCEN | 1.6 (1/16) | 1.6 (1/16) | 5 to 6 | 6 to 8 (13 to 17) |
| Steel or stainless | 3 mm (1/8 in) | 90 to 140 | DCEN | 2.4 (3/32) | 2.4 (3/32) | 6 to 7 | 7 to 9 (15 to 19) |
| Steel or stainless | 5 mm (3/16 in) | 140 to 200 | DCEN | 2.4 to 3.2 (3/32 to 1/8) | 2.4 to 3.2 (3/32 to 1/8) | 7 to 8 | 8 to 10 (17 to 21) |
| Steel or stainless | 6 mm (1/4 in) or more, multipass | 180 to 250 | DCEN | 3.2 (1/8) | 3.2 (1/8) | 8 | 9 to 12 (19 to 25) |
| Aluminum | 1.5 to 2 mm (1/16 to 5/64 in) | 70 to 110 | AC | 1.6 to 2.4 (1/16 to 3/32) | 1.6 to 2.4 (1/16 to 3/32) | 6 to 7 | 7 to 9 (15 to 19) |
| Aluminum | 3 mm (1/8 in) | 110 to 160 | AC | 2.4 (3/32) | 2.4 to 3.2 (3/32 to 1/8) | 7 to 8 | 8 to 10 (17 to 21) |
| Aluminum | 5 to 6 mm (3/16 to 1/4 in) | 170 to 250 | AC | 3.2 (1/8) | 3.2 (1/8) | 8 | 10 to 12 (21 to 25) |
Lessons 5, 6 and 8 explain each column. Like everything else in our Steel Knowledge Hub, the chart is free to consult on the Indumor site.
Steel, stainless or aluminum, with the settings each joint calls for.
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