How do you calculate winding scrap cost?

Multiply scrapped windings by cost per winding and by the share charged to this line or period for variable cost, then add fixed containment. With 100 windings at $45, an 80% share and $250 fixed, variable cost is $3,600 and total is $3,850.

What does cost per scrapped winding include?

It should be the fully loaded cost at the point of scrap: copper magnet wire, insulation, varnish if already cured, and the labor and machine time invested in winding and insertion. Scrapping later in the process means a higher per-winding cost.

Why apply a share charged to this line or period?

When scrap comes from multiple lines or spans a reporting period, the share allocates only the relevant portion. At 80% you are charging most but not all of the scrap value to this line, which keeps cost accounting honest.

What is a good winding scrap cost or scrap rate?

Target depends on grade and complexity, but mature winding lines push first-pass yield into the high 90s. Rather than a dollar benchmark, track scrap cost as a share of total winding material cost and drive it down period over period.

Does this include the cost of rework?

No. This calculator values windings that are scrapped outright. If some defective windings are reworked and recovered, exclude them from the scrapped count and track rework labor separately, since rework cost is usually lower than full scrap.

Scrapped windings vs cost per winding — which should I attack first?

Reducing the scrapped count attacks the root defect and is usually the durable win; lowering cost per winding by scrapping earlier in the process only limits the damage. Both scale variable cost equally, but prevention beats earlier detection.

Motors, Generators & Electrification Equipment calculator

Winding scrap cost Calculator

Winding scrap cost is the money lost to rejected stator and rotor windings — coils that fail surge, hipot or resistance test, or get damaged in handling — plus the fixed containment effort to chase the problem. Quality engineers and cost accountants in motor and generator plants use it to size the financial case for a yield project, since a scrapped winding carries fully loaded copper, insulation, varnish and labor. Because winding is early in the build, a scrapped coil can also strand downstream lamination and assembly cost. Tracking scrap dollars per line or period turns a vague defect rate into a number that justifies fixturing, training or tooling fixes.

What this calculator does

Estimate the cost of scrapped motor and generator windings so quality and cost teams can size copper and labor loss, compare scrap scenarios, and target winding yield improvement.
Use it when winding scrap is going through a weighted-cost review and you need a defensible loss figure for the line or period.
It computes total winding scrap cost by combining the allocation-adjusted variable scrap value with the fixed containment cost for the line or period.

Formula used

Variable winding scrap cost = scrapped windings × cost per scrapped winding × share charged to this line or period
Total winding scrap cost = variable winding scrap cost + fixed containment cost

Inputs explained

Scrapped windings:
Cost per scrapped winding:
Share charged to this line or period:
Fixed containment cost:

How to use the result

Use it when building a yield-improvement business case, allocating scrap to a line or month, or quantifying the cost of a winding defect spike.
It values scrap at a flat cost per winding and does not capture stranded downstream cost, opportunity cost of lost capacity, or rework that recovers some windings rather than scrapping them.

Current U.S. benchmarks

The producer price index for copper and brass mill shapes stands at 559.593 (BLS, May 2026), up 76.8% from a year earlier. Quotes priced off last quarter's material cost miss this move. Global copper trades at $13,484 per tonne (IMF via FRED, May 2026).
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 5,397 electrical equipment and appliances establishments employing about 369,437 workers (Census County Business Patterns, 2023).

Common questions

How do you calculate winding scrap cost? Multiply scrapped windings by cost per winding and by the share charged to this line or period for variable cost, then add fixed containment. With 100 windings at $45, an 80% share and $250 fixed, variable cost is $3,600 and total is $3,850.
What does cost per scrapped winding include? It should be the fully loaded cost at the point of scrap: copper magnet wire, insulation, varnish if already cured, and the labor and machine time invested in winding and insertion. Scrapping later in the process means a higher per-winding cost.
Why apply a share charged to this line or period? When scrap comes from multiple lines or spans a reporting period, the share allocates only the relevant portion. At 80% you are charging most but not all of the scrap value to this line, which keeps cost accounting honest.
What is a good winding scrap cost or scrap rate? Target depends on grade and complexity, but mature winding lines push first-pass yield into the high 90s. Rather than a dollar benchmark, track scrap cost as a share of total winding material cost and drive it down period over period.
Does this include the cost of rework? No. This calculator values windings that are scrapped outright. If some defective windings are reworked and recovered, exclude them from the scrapped count and track rework labor separately, since rework cost is usually lower than full scrap.

Last reviewed 2026-05-12.