The Tack Box · Weld Cost

Flux-core welding cost per inch

Flux-core (FCAW) lays down metal fast in any position, which keeps it cheap per inch on thick plate and long structural welds. This page prices FCAW welds by the inch with the calculator locked to flux-core defaults. Self-shielded wire trades some efficiency for going gasless in the wind.

Quick answer

A 1/4-inch flux-core fillet runs about $0.55 per inch ($6.60 per foot) at $85/hr on .045 wire. FCAW deposits fast (8 lb/hr for .045, up to 14lb/hr for 1/16"), so arc time and labor stay low. Slag cleanup is the tradeoff, and gas-shielded wire is about 86% efficient. It is the workhorse for outdoor structural and heavy plate.

Worked example: 12 inches of 1/4-inch fillet

Setup: FCAW, .045 E71T-1 (gas-shielded flux-core) at 8 lb/hr, 86% efficiency, 30% operating factor, C25 for flux-core at 35 CFH and $0.35/cf, $85/hr shop rate, 25% markup, wire at $3.80/lb. These are the numbers the calculator above loads with.

  • Labor: $4.52
  • Filler (flux-core wire): $0.56
  • Shielding gas: $0.20
  • Total cost: $5.28
  • Sell price at 25% markup: $6.60. That is $0.55 per inch, $6.60 per foot.

The MIG tab defaults to .035 wire, which comes out at $1.02 per inch on the same weld. Most of that gap is wire size, not process: .045 solid wire in spray transfer deposits about 8 lb/hr, the same as .045 flux-core. Factor a little extra labor for slag cleanup on appearance-critical work.

Gas-shielded flux-core (E71T-1) is the production choice for thick plate; self-shielded (NR-211) goes gasless for windy outdoor work at a lower efficiency. Where flux-core pulls ahead of solid wire is keeping that deposition rate out of position and on mill scale, where spray transfer can't go. The cost to watch is the extra labor for chipping and wire-wheeling slag: light on structural work, heavier when the weld has to look clean.

Questions welders keep asking

How much does flux-core welding cost per inch?

At the calculator's defaults (8 lb/hr deposition, 86% efficiency, 30% operating factor, $85/hr, 25% markup), a 1/4-inch fillet sells for about $0.55 per inch ($6.60 per foot). Larger wire (.052 or 1/16") deposits even faster and drops the per-inch number further on heavy plate.

Is flux-core cheaper than MIG?

Compare them at the same wire size. .045 gas-shielded flux-core and .045 solid wire in spray transfer both deposit about 8 lb/hr, so labor comes out close, and solid wire is a bit more efficient (95% vs 86%). Flux-core wins when the weld is out of position or the steel is dirty, because spray transfer only runs flat and horizontal. Against .035 short-circuit MIG, the common small-shop wire, flux-core deposits about 2 times as fast and is usually cheaper per inch on thick plate. Add slag cleanup time and the gap narrows.

Gas-shielded vs self-shielded flux-core: which costs less?

Gas-shielded (E71T-1) is about 86% efficient but you pay for shielding gas; self-shielded (NR-211) skips the gas but runs around 78% efficient and wastes more wire. In the shop, gas-shielded usually edges out on total cost and weld quality. Outdoors in wind, self-shielded wins because it works where gas-shielded simply will not. The calculator lets you set efficiency and gas flow to compare your own case.

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