Calculators · Welder
Welding Heat Input Calculator (kJ/mm)
Short answer
Arc energy in kJ/mm is volts × amps × 60 ÷ (travel speed in mm/min × 1,000). At 24 V, 200 A and 300 mm/min, that is 0.96 kJ/mm. Some procedures multiply by a thermal efficiency factor for the process; leave it at 1 to get arc energy.
- Heat input
- 0.96 kJ/mm
- Per 25.4 mm (1 in)
- 24.38 kJ/in
Formula
HI (kJ/mm) = V × A × 60 × η ÷ (Travel mm/min × 1000)
Worked example
24 V × 200 A × 60 = 288,000 J/min. Divided by 300 mm/min = 960 J/mm = 0.96 kJ/mm.
Before you rely on it
- Your welding procedure specification sets the heat-input range. Use the efficiency factor only if your procedure or standard calls for it.
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