Contactors & Motor Starters: The Silver Hotspots

A breaker switches rarely; a contactor switches constantly — starting motors, cycling loads, doing the daily work of a plant. Frequent switching means bigger contacts, designed to survive the arc erosion that comes with the job. That's why contactors, frame for frame, carry the most generous silver-alloy contacts in common electrical gear.

One trade buyer's teardown analysis describes large contactors (NEMA sizes 3–6, 150A and up) as carrying very high silver content relative to the device — treating that as a trade estimate, not an assay, the pattern is consistent: the harder a device switches, the more contact metal it carries.

A contactor is an electromagnetically held switch: a coil (copper windings) pulls in an armature when energized, driving contact bridges against stationary contacts — three poles for three-phase work. Release the coil and springs snap everything open. The silver-alloy tips sit at every bridge-to-stationary mating face: six contact points per three-pole unit, each larger than a breaker's.

Auxiliary contacts on the sides handle control logic with smaller precious-metal contacts of their own. The enclosure is steel; the current path is copper; the value concentrates at the tips.

A motor starter is essentially a contactor paired with overload relays — thermal elements (bimetal again) that protect the motor much like a breaker's thermal trip protects a circuit. NEMA-rated starters in larger sizes are the ones to notice: big contactors, real contact metal, and strong intact resale as industrial surplus.

Combination starters add a disconnect or breaker in the same enclosure — more copper, more steel, more everything. A panel full of starters is a serious lot.

Control relays switch small currents, so their contacts run small — but high-quality relays and precision instruments use gold-plated silver or gold contacts, since gold over nickel is the classic finish for low-voltage signal circuits that must stay clean. Gold flash also appears on PCB edge connectors in PLCs and control electronics — real, but measured in microns and valuable in aggregate, not per relay.

The honest framing: relays contribute gold flash and small silver contacts across a control panel's population. It's a volume game — and control panels full of relays are absolutely something we buy.

Photograph what you have — labels, nameplates, and overall quantity — and send it to Ironcrest for today’s offer. We buy electrical surplus nationally and coordinate pickup from your site.

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

Related reading: How much silver? →  |  Contact alloys →  |  Sell contactors & starters →

Do contactors have more silver than breakers?

Generally yes, frame for frame. Contactors switch constantly under load, so they're built with larger silver-alloy contacts than a breaker of similar rating. Large NEMA contactors are among the richest common sources.

What is a NEMA size on a motor starter?

NEMA sizes (00 through 9) standardize starter/contactor ratings by motor horsepower and current. Bigger NEMA size means bigger device, bigger contacts, and — typically — stronger resale demand as surplus.

Are relay contacts worth anything?

Individually, very little — they're small. In aggregate across control panels, plus gold-flash plating on connectors, control gear adds up. We buy control panels and relay lots as complete units.

Should I strip contactors for the contacts?

The same rule as breakers applies: large industrial contactors often have real intact resale value as surplus — especially named brands in working condition. Identify first, then decide.

Does Ironcrest buy contactors and motor starters?

Yes — contactors, motor starters, relays, and complete control panels are core electrical surplus for us. Photograph the labels (brand, NEMA size, coil voltage) and send them over.