These MIG values are a first-pass setup aid for welding steel with solid wire. They summarize Miller’s recommended amperage ranges by wire diameter and the corresponding wire-feed multiplier. The table shows calculated feed-speed endpoints from those published ranges. It does not provide a universal voltage, gas, or procedure setting because those depend on the machine, filler classification, joint, position, and approved welding procedure.

Use amperage and wire diameter together

Miller gives approximate ranges of 30–130 A for 0.023-inch wire, 40–145 A for 0.030-inch wire, 50–180 A for 0.035-inch wire, and 75–250 A for 0.045-inch wire. The ranges overlap; that does not mean the wire sizes are interchangeable in every joint. Select a wire classification and diameter compatible with the material, machine, contact tip, drive rolls, and required weld. The thickness-to-amperage rule in the source is only a rule of thumb for a starting estimate.

The feed-speed multiplier converts an estimated amperage to an initial wire-feed speed. For example, the guide uses 2 inches per minute per amp for 0.030-inch wire. At 100 A, that yields 200 ipm as a starting calculation. The displayed minimum and maximum are mathematical endpoints of Miller’s ranges, not a promise that every intermediate setting will produce an acceptable weld on a particular machine.

Voltage must come from the machine setup

Voltage affects bead height and width and must be matched to the wire-feed speed, power source, stickout, and transfer mode. Miller recommends starting with the machine manual or its setup chart, then making a test weld and refining the voltage. If the wire stubs into the work, the voltage may be too low; an unstable arc or burning at the contact tip can indicate that it is too high. These observations are troubleshooting cues, not an acceptance criterion for a code weld.

Do not infer a voltage value from the amperage or feed-speed multipliers in this table. Input line voltage, machine model, process controls, and wire classification all affect the available procedure. Use the exact equipment manual and any qualified Welding Procedure Specification. Set polarity to the wire maker’s recommendation and confirm gas composition and flow against the electrode data sheet. Outdoor drafts, poor coverage, leaks, and excess flow can all create shielding problems.

Prove out the joint safely

Joint design, fit-up, base-metal thickness, position, travel speed, contact-tip-to-work distance, and thermal conditions affect the result. Clean the work, use compatible consumables, and test on representative material before welding the part. Inspect bead profile and tie-in, then verify the required inspection and mechanical-property criteria. A visually smooth bead alone does not establish soundness or code compliance.

Keep the selected wire, shielding gas, machine model, input supply, voltage, wire-feed speed, polarity, and test results with the setup record. If any of these are changed, recheck the procedure requirements rather than treating the table as a controlled recipe. Follow the machine manual, filler-metal classification, and applicable welding code. The table is educational guidance and cannot qualify a welding procedure or replace qualified welding-engineer review.

A wire-feed estimate is especially sensitive to unit handling. The table uses inches per minute; if a machine displays meters per minute, divide by 39.37. Check that the feeder is calibrated and that the wire diameter on the spool agrees with the contact tip and drive-roll markings. A worn tip, slipping roll, kinked liner, or unusually long stickout can make delivered current and arc behavior differ from the estimate. Correct the feed system and setup before compensating by changing the procedure variables.

Source: MillerWelds, MIG Welding: Setting the Correct Parameters, published June 30, 2025. Feed-speed endpoints are calculated from the manufacturer’s wire-size multipliers and amperage ranges.