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What voltage and current ranges are used in a welding arc?

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Welder in a blue uniform and protective helmet using shielded metal arc welding to join metal pieces, with bright sparks and smoke visible at the welding point. — welding Shielded metal arc welding.

In the context of arc welding, the electric arc functions as a high-current, low-voltage discharge. The typical operating ranges for these parameters are as follows:

Current: 10–2,000 amperes1
Voltage: 10–50 volts1

This discharge creates the necessary heat to melt the filler metal and the base materials being joined. While the arc column is complex, it generally consists of a cathode that emits electrons, a gas plasma that conducts the current, and an anode region that becomes hotter than the cathode due to electron bombardment. These processes can utilize either direct current or alternating current depending on the specific application.12