Electric motors, alternators and starters — what drives the price

Electric motors are not priced by gross weight but by the estimated copper yield from the winding. We explain how alternators, starters and industrial motors are valued, and whether it pays to strip them down yourself.

An electric motor is priced through the copper in its winding, not through the reading on the weighbridge. This is the most common source of misunderstanding: the supplier looks at the weight, the buyer looks at how much tradeable metal that weight will actually leave behind. Below is the mechanism behind the valuation.

Why gross weight is not enough

A typical motor has three layers of value. The copper winding — the material proper. The lamination stack of stator and rotor — electrical steel, of markedly lower value. The housing — cast iron or aluminium, plus bearings, fan and terminal box.

The heavier the housing relative to the winding, the lower the rate per kilogram for the whole unit — at the same amount of copper inside. Two motors of identical weight can therefore be valued differently, and a "lighter" motor can be worth more than a heavier one. It is the same relationship we describe for the copper price: what counts is metal yield per tonne, not the tonne itself.

Alternators and starters

These are the most repeatable items in the family — they reach us from workshops, service centres and automotive plants. They are small, similar in construction and arrive in quantity, so we usually settle them in bulk, by type and batch mass rather than unit by unit.

Separating alternators from starters into two containers takes a moment and simplifies the settlement — the two groups have a different copper share.

Industrial motors and maintenance

Motors from production lines, pumps, fans and gearboxes are the typical stream of a maintenance department. Here the valuation is individual: construction differences between motors of the same rated power can be considerable, and for units above a tonne the method of loading matters too.

For such items the most useful thing is a photo of the rating plate — power, speed and type allow the construction to be estimated without an inspection on site.

Rotors, stators and small transformers

If motors are dismantled at your site for other reasons — servicing, refurbishment, parts recovery — separate trade items arise from that:

Stators with winding — priced by copper share.
Rotors — squirrel-cage and wound rotors settle differently. A cage can be aluminium or copper, so we check the conductor material before pricing.
Small transformers and coils — fines with a high share of lacquered copper.

Winding wire is lacquered, so it is not the same as clean Millberry — it is a separate, lower-priced grade.

Is it worth stripping a motor yourself

Usually not. Stripping means hours of work per tonne, and the difference between the rate for a complete motor and for recovered winding rarely covers it. Exceptions occur with large motors and at plants that have dismantling in their process anyway.

There is, however, one thing that genuinely raises the value of a batch and costs nothing: do not mix motors with other steel scrap. Motors thrown into a container with general steel will settle as steel.

What to prepare for a valuation

Four things are enough for a sensible valuation: the type of item (alternators, mixed motors, large motors), an approximate quantity in tonnes or units, photos of the batch, and the location. For unusual constructions, add a photo of the rating plate.

Do you have a regular stream of motors or a one-off batch to settle? Send photos — we will price your electric motors by type and actual yield, not by gross weight.

Frequently asked questions

What determines the price of an electric motor in scrap buying?

Above all the estimated copper yield from the winding relative to the mass of the whole motor. A heavy cast iron housing adds weight but not value, which is why the rate per kilogram is lower than for copper alone. The type and size of the motor and whether it comes complete or with ancillaries also matter.

Do you have to extract the copper from a motor before selling it?

Usually it is not worth it. Stripping a motor is time-consuming work, and the difference between the rate for a whole motor and for recovered winding rarely covers that cost — particularly at larger quantities. We accept motors complete and price them by type and estimated yield.

How does pricing an alternator differ from an industrial motor?

Alternators and starters are small, repeatable items — we usually settle them in bulk, by type and batch mass. Large industrial motors are valued individually, because they differ in construction, copper share and handling. For single units above a tonne it is worth sending a photo of the rating plate.