Welding Heat Input
kJ/mm from amps, volts and travel speed — MMA, MIG, TIG, SAW
Flags amps outside the typical packet range for that wire, rod or tungsten.
A
Reading 180 A
V
Reading 22 V
mm/min
Time a run: length ÷ minutes. 150mm in 30 seconds is 300 mm/min.
Results
Heat input
0.63kJ/mm
Per inch
16.1kJ/in
Arc energy (no k)0.79 kJ/mm — 22 V × 180 A × 60 ÷ 300 mm/min
Thermal efficiency k0.8 (MIG / MAG solid wire (131 / 135), BS EN 1011-1)
Band (carbon steel, indicative)moderate — the WPS sets the real limits
Watts at the arc3960 W
Estimates use standard UK trade rules of thumb. Always check the bag/spec on the day.