Rare Earth Magnet & Motor Materials worked example

Rework Cost at 81% salvageable share: a worked example in rare earth magnet & motor materials

This scenario runs the rework cost calculation on the strong side: 81% salvageable share, with every other input held at its documented default. A magnet supplier weighs whether to salvage a batch of chipped NdFeB blanks or scrap them outright.

The inputs for this scenario

  • Magnets reworked: 400 pieces (unchanged)
  • Rework labor and remachining rate: 6.5 $/piece (unchanged)
  • Salvageable share: 81 % (raised for this scenario; the documented default is 70)
  • Recoat line setup charge: 850 $ (unchanged)

Working through the calculation

  • Applying the documented formula (Total rework = magnets reworked x remachining rate x salvageable share + recoat setup) to the inputs above produces each figure below.
  • At this operating point the engine returns 2,956 $ for total rework cost, the number this scenario is built around.
  • At this operating point the engine returns 7.39 $ / piece for rework cost per unit.
  • At this operating point the engine returns 2,106 $ for variable rework cost.
  • At this operating point the engine returns 850 $ for fixed rework cost adder.

How this compares with the baseline

  • Against the tool's baseline example, where salvageable share sits at 70% and the headline result is 2,670 $, this scenario comes in 10.71% above the baseline at 2,956 $.
  • Use it when a magnet lot fails final coating adhesion, dimensional, or Br/Hc inspection and you must choose between reworking and scrapping. Treat this as a target state: the delta against the baseline quantifies what the improvement is worth before you commit to chasing it.

Results at a glance

  • Total rework cost: 2,956 $ (headline result)
  • Rework cost per unit: 7.39 $ / piece
  • Variable rework cost: 2,106 $
  • Fixed rework cost adder: 850 $

Run it with your numbers

  • Every input above is editable in the live Rework Cost calculator, which recalculates instantly and can be shared with the inputs intact.

Last reviewed 2026-05-12.