How do you calculate weldment fabrication cost?

Multiply welding labor hours by the loaded shop rate and the productive arc-time percentage, then add the consumables and gas charge. With 120 hours at $85/hr, 70% arc-time and $1,800 of consumables, that is 120 x 85 x 0.70 + 1,800 = $8,940 total.

Why apply a productive arc-time percentage instead of just hours times rate?

Because a welder's clock hours include fit-up, repositioning, slag removal and waiting on cranes. Applying 70% arc-time to the $7,140 labor portion reflects that the torch is actually depositing metal only part of the shift, which is realistic for heavy mining weldments.

What is a good arc-time percentage for mining weldments?

Manual stick or MIG on large structures often runs 20-35% true arc-on time; semi-automated and well-fixtured booths can reach 50-70%. The 70% default here represents an efficient, well-jigged production cell, so check it against your own booth before quoting.

What does the cost per labor hour figure tell me?

It is total cost divided by welding hours - here $8,940 / 120 = $74.50 per piece-hour. It rolls labor, overhead capture and consumables into one number you can benchmark against past jobs or a target booth rate.

How do I split fixed and variable cost on a weldment?

The labor-and-arc-time portion (here $7,140) scales with the size of the weld, so it is variable; the $1,800 consumables and gas charge is the fixed adder for this job. Knowing the split helps when you scale the quote up or down in volume.

Should consumables include wire, flux and shielding gas?

Yes - the consumables and gas charge should cover filler wire or electrodes, flux, shielding gas, contact tips, nozzles and grinding media. On a $8,940 weldment, $1,800 of consumables is about 20%, which is typical for high-deposition mining work.

Mining Vehicle & Underground Equipment calculator

Weldment Fabrication Cost Calculator

Weldment fabrication cost tells you what it actually costs to build a fabricated structure - a haul truck tray, a loader bucket, a scaler boom, or a mine duct - from the welding labor, shop overhead, productive arc-time and consumable spend. Estimators and fabrication shop managers in mining-equipment OEMs and rebuild shops use it to quote weldments and to check whether quoted hours match what the booth can really produce. Arc-time is the lever most people get wrong: a welder is paid for 8 hours but the torch is only lit for a fraction of that, so loading 100% of labor at full deposition badly overstates throughput and understates cost per real weld inch. This calculator forces you to state arc-time explicitly, so the quoted cost reflects the floor, not the spec sheet.

What this calculator does

Estimate the cost to fabricate a heavy steel weldment such as a dump-truck frame or LHD chassis for mining and underground equipment.
A fabrication shop quoting the welded frame for a haul truck bed or underground loader before machining and assembly.
Computes total weldment fabrication cost by multiplying welding labor hours by the loaded shop rate and productive arc-time percentage, then adding consumables and gas, and breaks out variable vs fixed cost.

Formula used

Fabrication cost = welding hours x shop rate x productive arc-time % + consumables
Cost per labor hour = total cost / welding hours

Inputs explained

Welding labor hours:
Loaded shop rate:
Productive arc-time:
Consumables and gas charge:

How to use the result

Use it when quoting a fabricated mining weldment, validating a subcontractor's labor estimate, or comparing in-house fabrication against an outside buy.
It treats arc-time as a single capture factor applied to labor cost; it does not separately model fit-up, tacking, grinding, NDT or weld-repair rework, which on heavy mining weldments can rival the welding time itself.

Current U.S. benchmarks

U.S. light vehicles sell at a 16.9 million annual rate (BEA, Jun 2026), up 4.1% from a year earlier, the volume signal for automotive supply chains.
Steel mill PPI stands at 348.53 (BLS, May 2026), up 6.7% from a year earlier. New factory orders are up 2.3% year over year (Census).
The U.S. has 11,691 transportation equipment establishments employing about 1,682,910 workers (Census County Business Patterns, 2023).

Common questions

How do you calculate weldment fabrication cost? Multiply welding labor hours by the loaded shop rate and the productive arc-time percentage, then add the consumables and gas charge. With 120 hours at $85/hr, 70% arc-time and $1,800 of consumables, that is 120 x 85 x 0.70 + 1,800 = $8,940 total.
Why apply a productive arc-time percentage instead of just hours times rate? Because a welder's clock hours include fit-up, repositioning, slag removal and waiting on cranes. Applying 70% arc-time to the $7,140 labor portion reflects that the torch is actually depositing metal only part of the shift, which is realistic for heavy mining weldments.
What is a good arc-time percentage for mining weldments? Manual stick or MIG on large structures often runs 20-35% true arc-on time; semi-automated and well-fixtured booths can reach 50-70%. The 70% default here represents an efficient, well-jigged production cell, so check it against your own booth before quoting.
What does the cost per labor hour figure tell me? It is total cost divided by welding hours - here $8,940 / 120 = $74.50 per piece-hour. It rolls labor, overhead capture and consumables into one number you can benchmark against past jobs or a target booth rate.
How do I split fixed and variable cost on a weldment? The labor-and-arc-time portion (here $7,140) scales with the size of the weld, so it is variable; the $1,800 consumables and gas charge is the fixed adder for this job. Knowing the split helps when you scale the quote up or down in volume.

Last reviewed 2026-05-12.