Get a rough amperage ceiling reference, then tune with your machine, pedal and actual joint.
Reviewed 2026-10-07
The familiar 1 amp per .001 in thickness idea is only a rough reference for DC TIG on steel/stainless. Aluminum AC, outside corners, fillets, thick fixtures and preheated parts behave differently.
Verify polarity/AC mode, tungsten type and diameter, cup/gas flow, clean material, filler compatibility and a solid work connection before blaming amperage.
Running too much gas, contaminated tungsten, dipping filler into the tungsten, and trying to hold full pedal instead of using amperage as a ceiling.
Tools that match this task — not a random product wall.
It is a rough carbon-steel/stainless TIG starting reference, not a procedure. Joint design, position, pulse, alloy and heat sink change the need.
DCEN is common for steel and stainless TIG. Aluminum is commonly welded on AC with suitable equipment.
Match base metal and service requirements. Use the TIG filler selector and manufacturer/code guidance.