How do you calculate steel plate yield?

Divide rejected plates by total plates fabricated and multiply by 100. With 8 rejects out of 250 plates, the reject rate is 8 ÷ 250 × 100 = 3.2%, so plate acceptance is 96.8%.

What is a good steel plate yield in heavy-civil fabrication?

For structural plate work many shops target rejects below 2-3% of a batch, with acceptance well into the high 90s. The 3.2% here is slightly above a tight target and worth a defect-type review, though it depends on plate thickness and tolerance class.

Does this measure scrap or rework?

It measures total rejects at inspection. It does not split fully scrapped plates from those that can be re-cut or re-beveled, so pair it with a rework-versus-scrap breakdown for true cost impact.

What does the gap to target represent?

The calculator reports 91.8 points as the distance between the 3.2% reject figure and the 95% target reference. Treat it as headroom against benchmark rather than a direct acceptance yield.

What drives steel plate rejects?

Poor plasma or oxy-fuel edge quality, out-of-flat plate from the mill, incorrect bevel angles for weld prep, and dimensional drift from thermal distortion during cutting. Track by defect code to find the dominant cause.

How is plate yield different from weld yield?

Plate yield judges the base plates before or at fabrication inspection. Weld yield judges the joints after welding via NDT. A plate can pass plate inspection and still fail later at weld inspection.

Tunnel Boring & Heavy Civil Equipment calculator

Steel Plate Yield Calculator

Steel plate yield tracks the share of fabricated steel plates — for TBM shields, segment moulds, gantry structures, or backfill hoppers — that fail inspection against dimensional, flatness, or weld-prep criteria, expressed as a percentage of the batch. Fabrication quality engineers and heavy-civil workshop supervisors use it to catch cutting, forming, and material problems before plates reach assembly. Because a rejected structural plate can hold up an entire sub-assembly, even a low reject percentage carries outsized schedule risk. Tracking it by batch and by defect type exposes whether the issue is plasma-cut edge quality, plate mill certification, or bevel prep.

What this calculator does

Estimate steel plate yield for tunnel boring and heavy civil equipment using production-ready inputs so teams can track KPI performance and decide whether corrective action is needed.
Use it when steel plate yield in tunnel boring and heavy civil equipment needs a clean rate and gap-to-target you can put on a tier board.
It computes the percentage of fabricated steel plates rejected at inspection and the gap between that reject rate and your target acceptance benchmark.

Formula used

Steel plate yield rate = steel plate yield count ÷ total steel plate yield population × 100
Steel plate yield gap to target = steel plate yield rate - target steel plate yield rate

Inputs explained

Steel plates rejected at inspection:
Total steel plates fabricated:
Target plate acceptance rate:

How to use the result

Use it per fabrication batch or per shift to monitor plate quality feeding heavy-civil sub-assemblies and shield structures.
It is an aggregate reject ratio and does not separate defect types or distinguish scrap from reworkable plates, which have very different cost and schedule impacts.

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 steel plate yield? Divide rejected plates by total plates fabricated and multiply by 100. With 8 rejects out of 250 plates, the reject rate is 8 ÷ 250 × 100 = 3.2%, so plate acceptance is 96.8%.
What is a good steel plate yield in heavy-civil fabrication? For structural plate work many shops target rejects below 2-3% of a batch, with acceptance well into the high 90s. The 3.2% here is slightly above a tight target and worth a defect-type review, though it depends on plate thickness and tolerance class.
Does this measure scrap or rework? It measures total rejects at inspection. It does not split fully scrapped plates from those that can be re-cut or re-beveled, so pair it with a rework-versus-scrap breakdown for true cost impact.
What does the gap to target represent? The calculator reports 91.8 points as the distance between the 3.2% reject figure and the 95% target reference. Treat it as headroom against benchmark rather than a direct acceptance yield.
What drives steel plate rejects? Poor plasma or oxy-fuel edge quality, out-of-flat plate from the mill, incorrect bevel angles for weld prep, and dimensional drift from thermal distortion during cutting. Track by defect code to find the dominant cause.

Last reviewed 2026-05-12.