millermatic 251 settings for 3/4 in thick steel

by Jeff King
(Hudsonville Mich.)

using a millermatic 251 mig welder with .035 wire.Doing fillet welds and corner welds. I would like to do in one pass so that it looks nice. I can not seem to get the correct wire speed an voltage necessary to get a nice looking weld. Yes I am able to rotate the weldment in whatever position is necessary.Have been doing all welds facing up. Welder shows 1/2 steel as maximum, on reference chart on side panel. What is my next step?


IF you can position to where the welding direction is somewhat uphill, you can carry a bigger puddle but I dont think you are going to be able to do it in one pass on 3/4" thickness.

You might have to settle for 2 passes.
the 1/2" limit on your millermatic 251 is meant for single pass welds. You can go thicker with multi pass.

I would use the 3/8" or 1/2" settings but maybe a bit less wire speed than miller lists...At least try trimming the wire speed back and see if it gets smoother. The wire speed settings are most always too high in my opinion

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