Cost per metre of weld
What a metre of weld really costs once the filler, the gas, the electricity and the hours are all counted — the number you need before quoting, not after.
Where the money goes
The calculation starts from the groove cross-section, converts it to deposited metal, then adds losses to get the filler actually consumed. Gas follows from the arc time. Electricity follows from current, voltage and the efficiency of the source. Labour follows from arc time divided by the share of the shift spent under the arc.
That last input is the one that decides the answer. Stick welding runs at 25–35 % arc-on time, semi-automatic at 40–55 %. Everything else is fitting, tacking, changing electrodes, chipping slag and moving. Quotes that assume a welder welds all day are the usual reason a job loses money.
What actually makes it cheaper
Not the price of the filler — it is rarely more than a fifth of the total. Labour dominates, so anything that reduces arc time or rework wins: a smaller groove angle, correct fit-up, a process with a higher deposition rate, and welds that pass first time. Over-welding is the quiet killer: a fillet made 8 mm where the drawing asks for 6 costs 78 % more filler and just as much extra time, and it is not stronger.
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