Specialty Conductors: Tinned, Silver-Plated & Magnet Wire

Tinned copper is solid copper with a thin tin coating — silver-gray on the surface, reddish copper at any fresh cut or scrape. It is everywhere once you know to look: marine wiring, old cloth- and rubber-insulated house wire, and plenty of industrial hook-up wire. The number-one forum question in all of scrap copper — “tinned copper or aluminum?” — is answered in ten seconds with a knife: scrape the surface and copper shows through. Tinned copper grades separately from bare bright, but it is genuinely copper and genuinely bought.

Silver-plated copper shows up in RF, aerospace, and mil-spec hook-up wire — typically 30 through 12 AWG — where the plating serves high-frequency performance. Like tinned wire, it is copper underneath; a scrape or cut proves it. It will not grade as bare bright, but specialty and mil-spec surplus has its own buyers, and the copper content is real.

Magnet wire is copper coated in a thin enamel film — the windings inside motors, transformers, coils, and ballasts, from hair-fine 40 AWG up to 10 AWG. New it looks copper-colored; aged it can look dark or varnished. Scrape the enamel and bright copper appears. Motor shops, rewind shops, and transformer teardowns are the sources — and motor windings are one of the most overlooked copper stashes in industrial scrap.

Plated and enameled copper grades below bare bright — the coating is contamination from a refiner’s point of view — but it is still copper-bearing wire with real value, bought as its own category. The mistake is misidentifying it: tinned copper sold as aluminum (or aluminum sold as tinned copper) is how sellers leave money behind or lose credibility. When in doubt, scrape it, photograph the cut end, and ask. See the canonical grades guide for where each form lands.

Photograph what you have — the wire, any jacket markings, and the overall quantity — and send it to Ironcrest for today’s offer. We buy nationally and coordinate pickup from your site.

Sell your copper to Ironcrest →  |  Call or text 312-880-8174  |  Send photos →

See also: Solid copper vs. look-alikes  |  What type of copper wire do I have?  |  Copper wire grades guide (canonical)

Is tinned copper wire worth less than bare copper?

It grades below bare bright because the tin coating counts as contamination — but it is still solid copper underneath and still bought as its own category. The costly mistake is mistaking it for aluminum and selling it as such.

How do I tell tinned copper from aluminum?

Scrape the surface with a knife or make a fresh cut. Tinned copper shows reddish copper beneath the silver skin; aluminum is silver all the way through. Tinned copper is also noticeably heavier than aluminum wire of the same size.

What is magnet wire?

Copper wire coated in a thin enamel insulation, used for motor, transformer, and coil windings. Scrape the enamel and bright copper shows underneath. Motor shops and transformer teardowns are the main sources.

Is silver-plated wire actually silver?

No — it is copper wire with a thin silver plating, used in RF and mil-spec applications. The plating is a tiny fraction of the weight; the value is the copper underneath.

Where does magnet wire come from?

Electric motors, transformers, coils, ballasts, and relays — anywhere copper is wound. Motor rewind shops, HVAC teardowns, and industrial cleanouts produce it steadily.