How do you calculate weld rework cost?

Multiply the number of defective weld joints by the repair cost per joint, apply the reject rate as a decimal, and add the re-inspection setup. For 60 joints at $950 each, 70% reject rate, plus $12,000 setup: 60 x 950 x 0.70 + 12,000 = $51,900 total.

What does the reject rate applied represent?

It is the fraction of flagged joints that genuinely require rework after re-review. NDT flags are sometimes cleared on second look or by a more sensitive read; a 70% applied rate means 3 in 10 initial flags did not need physical repair.

What is a good weld reject rate in heavy civil fabrication?

For structural and pressure-retaining welds, sustained reject rates above 3-5% of joints usually signal a procedure, fit-up, or welder-qualification problem. The reject rate in this calculator is applied to already-flagged joints, not to all welds produced.

Should re-inspection setup be a fixed cost?

Yes. Mobilizing NDT technicians, re-establishing access, and re-issuing inspection paperwork happens roughly once per rework campaign regardless of how many joints are involved, so it sits as the $12,000 fixed adder.

What is the cost per defective joint in the example?

Total cost divided by joints: $51,900 divided by 60 equals $865 per defective joint. That blended figure includes the shared re-inspection setup, so it runs higher than the raw $950 repair applied at 70%.

Repair versus re-fabricate: how does this help?

If the per-joint rework cost approaches the cost of a fresh spool or segment, re-fabrication is often faster and lower-risk. Run the total here, then compare against a new-fabrication quote before committing to grind-and-reweld.

Tunnel Boring & Heavy Civil Equipment calculator

Rework Cost Calculator

On heavy civil steelwork, TBM segment moulds, and shaft fabrications, a rejected weld is not just steel to grind out; it is NDT re-shoots, WPS re-qualification, and schedule slip. This calculator prices a weld rework campaign by combining the count of defective joints, the loaded repair cost per joint, the reject rate actually applied after re-inspection, and the fixed cost of setting up re-inspection. QA/QC engineers, welding coordinators, and fabrication project managers use it to decide whether to repair in place or re-fabricate, and to feed cost-of-poor-quality metrics back to procedures and welders. Because weld rework compounds quietly across dozens of joints, quantifying it early keeps a fabrication run from silently blowing its margin.

What this calculator does

Estimates rework cost for heavy civil fabrication from defective joint count, per-joint repair cost, applied reject rate, and fixed re-inspection setup.
Use it when a weld-inspection report flags failures to budget the gouge-out, re-weld, and NDT recall before the assembly can be released.
It computes the total cost of a weld rework batch as the variable per-joint repair cost times the effective reject rate, plus a fixed re-inspection setup, and the cost per defective joint.

Formula used

Total = defective joints x repair cost x (reject rate ÷ 100) + re-inspection setup
Per joint = total cost ÷ defective weld joints

Inputs explained

Defective Weld Joints:
Repair Cost per Joint:
Reject Rate Applied:
Re-Inspection Setup:

How to use the result

Use it after an NDT report flags joints, or when deciding between repair, re-weld, or re-fabrication on a spool or segment.
It treats every defective joint as costing the same to repair; in reality a root-crack in a thick section costs far more than a surface porosity, so blend or segment your cost per joint for mixed defect types.

Current U.S. benchmarks

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).

Common questions

How do you calculate weld rework cost? Multiply the number of defective weld joints by the repair cost per joint, apply the reject rate as a decimal, and add the re-inspection setup. For 60 joints at $950 each, 70% reject rate, plus $12,000 setup: 60 x 950 x 0.70 + 12,000 = $51,900 total.
What does the reject rate applied represent? It is the fraction of flagged joints that genuinely require rework after re-review. NDT flags are sometimes cleared on second look or by a more sensitive read; a 70% applied rate means 3 in 10 initial flags did not need physical repair.
What is a good weld reject rate in heavy civil fabrication? For structural and pressure-retaining welds, sustained reject rates above 3-5% of joints usually signal a procedure, fit-up, or welder-qualification problem. The reject rate in this calculator is applied to already-flagged joints, not to all welds produced.
Should re-inspection setup be a fixed cost? Yes. Mobilizing NDT technicians, re-establishing access, and re-issuing inspection paperwork happens roughly once per rework campaign regardless of how many joints are involved, so it sits as the $12,000 fixed adder.
What is the cost per defective joint in the example? Total cost divided by joints: $51,900 divided by 60 equals $865 per defective joint. That blended figure includes the shared re-inspection setup, so it runs higher than the raw $950 repair applied at 70%.

Last reviewed 2026-05-12.