WeldingCalc

Home · Questions · Aluminum

What Size Welder Do I Need for Aluminum?

Full breakdown: TIG amps by material thickness.

The Millermatic 211 spec sheet lists aluminum, with a spool gun, from 18 gauge to 1/8 in on 120 V and from 18 gauge to 3/8 in on 240 V (Millermatic 211 spec sheet). The Handler 140 spec lists .030 aluminum wire without an aluminum thickness band (Handler 140 spec sheet). The farm guide calls stick marginal for aluminum and lists TIG from 22 gauge up, including .010 in, while the 1-amp-per-.001-in rule is stated for steel (Welding on the Farm, Miller parameters).

As an Amazon Associate I earn from qualifying purchases. The Amazon links below are affiliate links; they don't change the math.

MIG welder with spool gun aluminum

Published figures

FigureValueSource
Aluminum thickness, 120 V18 gauge–1/8 in, with spool gunMillermatic 211 spec sheet
Aluminum thickness, 240 V18 gauge–3/8 in, with spool gunMillermatic 211 spec sheet
120 V outputRated 115 A at 19.8 VDC, 20% duty; range 30–130 A; input 24.3 AMillermatic 211 spec sheet
240 V outputRated 150 A at 21.5 VDC, 40% duty; range 30–230 A; input 16.6 AMillermatic 211 spec sheet
Handler 140 aluminum wire.030 aluminum; machine range 25–140 A on 115 VHandler 140 spec sheet
Steel .023 and .030 windows, for contrast (MIG wire speed chart).023 in is 30–130 A; .030 in is 40–145 A. These windows are the steel chartMiller parameters
Stick on aluminumMarginalWelding on the Farm
TIG thin end22 gauge and up; can weld .010 inWelding on the Farm
Duty minutes at the rated points20 percent of 10 minutes = 2 min weld and 8 min cool; 40 percent = 4 min weld and 6 min coolWelding on the Farm

How to size it

  1. Split the question by supply voltage before picking an amp. On the Millermatic 211, 120 V aluminum is 18 gauge to 1/8 in and 240 V aluminum is 18 gauge to 3/8 in, and both require a spool gun (Millermatic 211 spec sheet). The same sheet’s steel limits are wider (24 gauge to 3/16 in on 120 V, 24 gauge to 3/8 in on 240 V); do not paste the steel line onto aluminum.
  2. Read the rated output that comes with each plug, not a steel rule of thumb. At 120 V the 211 is rated 115 A at 19.8 VDC and 20 percent duty, range 30–130 A, drawing 24.3 A. At 240 V it is rated 150 A at 21.5 VDC and 40 percent duty, range 30–230 A, drawing 16.6 A (Millermatic 211 spec sheet). Miller’s 1 amp per .001 in note is for steel with solid wire (Miller parameters). It is not used as an aluminum amperage on this page.
  3. Treat .030 aluminum wire as a published wire type, not as a thickness. The Handler 140 lists .030 aluminum along with .023–.035 solid and .030–.035 flux-cored, on a 115 V machine whose welding range is 25–140 A (Handler 140 spec sheet). That sheet does not state how thick an aluminum part those 25–140 A will weld.
  4. Keep the steel wire chart labeled as steel. .023 in steel wire is 30–130 A and .030 in steel wire is 40–145 A (Miller parameters). Those windows explain the steel diameters; they are not an aluminum procedure. The MIG wire speed chart is that steel chart.
  5. For process choice, use the farm guide’s actual words: stick is marginal for aluminum, and TIG is listed from 22 gauge up and can weld .010 in (Welding on the Farm). Duty cycle is still a 10-minute cycle. Twenty percent is 2 minutes welding and 8 minutes cooling; 40 percent is 4 and 6. The duty cycle calculator applies a nameplate. Aluminum bands here are the 211 spec sheet, including the spool-gun note, not a weld trial.

dual voltage MIG welder 120V 240V

Frequently asked questions

How thick an aluminum weld does a Millermatic 211 list?

On 120 V, 18 gauge to 1/8 in. On 240 V, 18 gauge to 3/8 in. Both lines say aluminum with a spool gun (Millermatic 211 spec sheet).

What aluminum wire does the Handler 140 spec list?

.030 aluminum wire, alongside .023–.035 solid and .030–.035 flux-cored (Handler 140 spec sheet). The sheet does not add an aluminum thickness range.

Is stick a fit for aluminum?

The farm guide calls stick marginal for aluminum (Welding on the Farm).

What output is published on the 211 while those thickness lines apply?

120 V is rated 115 A at 19.8 VDC and 20 percent duty, range 30–130 A. 240 V is rated 150 A at 21.5 VDC and 40 percent duty, range 30–230 A (Millermatic 211 spec sheet).

Affiliate

Affiliate disclosure: as an Amazon Associate, we earn from qualifying purchases — at no cost to you.

.023 MIG wire

Compiled with AI assistance from the sources below. Spot an error? Email [email protected].

Sources