How to set amperage and voltage in welding?

Setting amperage (current) and voltage happens in two steps: the starting range comes from the manufacturer's data sheet (electrode, wire, rod), then it is validated on a test coupon. No single table replaces those two steps: the same electrode diameter does not call for the same current in every position, joint type and thickness.

Where to read the values:

• SMAW — the current range per electrode diameter is printed on the packaging and in the manufacturer's data sheet (E6010, E7018, E7024); the company's WPS sets the one that applies to the joint.
• GMAW/FCAW — the wire manufacturer's data sheet gives the current/voltage pairs per diameter and per gas, as well as the wire feed speed; the WPS keeps the qualified setting.
• GTAW — the machine's data sheet and the WPS give the current for the material and thickness; the weld is judged on the pool, not on the display.

Visual indicators:

• Too hot: flat weld, too fluid, excessive spatter, excessive penetration
• Too cold: convex weld, lack of penetration, sticking, arc instability
• Well set: steady hiss, controlled weld pool, correct penetration