Welding & Fabrication worked example

Weld Metal Required at 61% deposition efficiency: a worked example

Here is what the math looks like when conditions slip. We hold every other input steady and drop deposition efficiency to 61%, then walk the calculation through step by step. Estimate filler metal needed from total weld length, weight of deposit per inch, and deposition efficiency.

The inputs for this scenario

  • Total weld length: 500 in (held at the documented default)
  • Weight of weld metal per inch: 0.03 lb / in (held at the documented default)
  • Deposition efficiency: 61 % (the input this scenario stresses; the baseline uses 85)

Working through the calculation

  • The calculation starts from the formula this tool documents: Deposited weld metal weight = total weld length × weight of weld metal per inch.
  • Filler metal required to purchase works out to 22.13 lb at these inputs, and this is the headline figure for the scenario.
  • Deposited weld metal weight works out to 13.5 lb at these inputs.
  • Spatter, slag, and stub loss allowance works out to 8.63 lb at these inputs.
  • Deposition efficiency works out to 61 % at these inputs.

How this compares with the baseline

  • Against the tool's baseline example, where deposition efficiency sits at 85% and the headline result is 15.88 lb, this scenario comes in 39.34% above the baseline at 22.13 lb.
  • The practical read: the gap between this scenario and the baseline is entirely attributable to deposition efficiency, so recovering it is worth quantifying in dollars before considering equipment or staffing changes. It assumes one uniform weld size across the whole length and a single deposition efficiency; multi-pass joints, varying fillet sizes, or a mix of processes need to be broken into segments and summed.

Results at a glance

  • Filler metal required to purchase: 22.13 lb (headline result)
  • Deposited weld metal weight: 13.5 lb
  • Spatter, slag, and stub loss allowance: 8.63 lb
  • Deposition efficiency: 61 %

Run it with your numbers

  • To rerun this with your own numbers, open the live Weld Metal Required calculator, set deposition efficiency to your actual value, and adjust the remaining inputs to match your operation.

Last reviewed 2026-05-12.