Production & Cost Control: Welding Economics, Lean Principles, Productivity
Where weld cost comes from
Weld cost per foot = (labor + consumables + equipment + power + overhead + rework and inspection) ÷ feet of acceptable weld. In manual processes labor dominates, often 70–85% of total cost, so anything that raises arc time per paid hour beats squeezing the consumable price.
The key lever is operating factor - arc time divided by total paid time. Typical values: SMAW 20–30%, GMAW 40–60%, FCAW 40–50%, SAW 60–80%, robotic cells 80–95%. Deposition rate (lb/hr of arc time) multiplied by operating factor gives lb per paid hour, which is what actually gets billed. Do not confuse deposition rate with melt-off rate, and never compare processes on arc-time cost alone.
Weld size is the quiet cost driver: fillet cross-section grows with the square of leg size, so doubling the leg quadruples the metal, time and cost. Over-welding is the most common hidden waste in a shop.
Worked example
A joint needs 4 lb of deposited metal. SMAW: 3 lb/hr arc time at 25% operating factor = 0.75 lb per paid hour, so 5.33 paid hours. GMAW: 5 lb/hr at 50% = 2.5 lb per paid hour, so 1.6 paid hours. At $40/hr fully burdened, that is $213 versus $64 per joint - a 70% saving that has nothing to do with electrode price.
Lean in the weld shop
Watch for the classic wastes: over-welding, waiting on fit-up, rework, motion fetching consumables, and inventory of WPS-less jobs. Tools: 5S around the station, point-of-use gas and wire, standard work tied to the WPS, first-pass yield tracking, and 5-Why root cause on every rework ticket.