What amperage rule is described if you need to weld with a general guideline?

• A. Amperage does not depend on thickness
• B. Amperage is constant at 100 A
• C. Amperage increases with thickness but not in a simple rule
• D. Amperage is about 1 amp per 0.001 inch of metal thickness

Answer: (D)

Amperage sets the heat you’re putting into the metal, and thicker metal needs more heat to melt and fuse properly. A practical starting point many shops use is a simple rule: about 1 amp for every 0.001 inch of metal thickness. This gives a straightforward way to pick a starting current. For example, welding metal that’s 0.125 inch thick would start around 125 amps. As you work, you’ll fine-tune the setting based on the welding process (MIG, stick, flux-core), the wire or electrode size, joint design, and position. Too little current can leave the weld cold and weak; too much can burn through thin metal or cause excessive bead buildup. While not universal for every situation, this guideline provides a reliable general starting point for estimating amperage across common sheet and plate thicknesses.