MIG starting calculator

Mild steel ballpark for ER70S-6 with C25 (75/25). Built from the common “1 amp per 0.001" thickness” rule and wire-speed multipliers — then tune on scrap.

Not a WPS. These are practice starting points only. They are not a Welding Procedure Specification, not code-qualified, and not a substitute for your machine chart or the wire manufacturer’s data. Always scrap-test before welding a real part.

Inputs

Base metal thickness

Solid wire diameter

Process

How this is calculated

Target amps ≈ thickness (inches) × 1000 (1 A per 0.001").
Wire speed ≈ amps × multiplier: 0.023"→3.5, 0.030"→2.0, 0.035"→1.6 IPM/A.
Voltage is a short-circuit starting band; raise if it stubs, lower if it’s harsh/spattery.
Gasless flux-core is a rough shift only — follow the wire label for polarity and WFS.

Check the bead photo TIG calculator

Joint design, position, stickout, and machine brand all move the window. If your door chart disagrees, trust the door chart first.