MICROSCRAPPINGE-waste field guide
TO-3 gold plated39 × 26 mm
TO-3 plain39 × 26 mm
TO-5 can9 × 7 mm
TO-220 — worthless10 × 15 mm

Drawn to true relative scale — the variants above are directly size-comparable.

RF, power & vintage · Tier B

Gold-plated hermetic transistors (TO-3/TO-5/TO-18)

A gold tint on the can AND the legs. Older military and industrial versions are gold-plated Kovar. Modern TO-220 and TO-247 plastic parts are worthless — epoxy, tinned steel and a copper or aluminium tab.

Au 0.5–2 g/lbBase Kovar
eBay typical$40–120per lb
Refiner pays$30per lb
Metal in it$157per lb at 4 Aug 2026 spot
Confidencelowof the yield figures

How to spot it

TO-3 oval metal can with two leads plus the case as the third terminal; TO-5/TO-18/TO-39 small round cans.

Metal content

MetalQuantityNotes
Gold0.5–2 g/lbheavily plated TO-3 up to 4 g/lb
Base metalKovar, steel, Cu

At 4 Aug 2026 spot prices that works out to $157 per pound of contained metal — Gold 1.2 g = $157. A refiner paying $30 returns about 19% of that, which is normal: refining costs money and the buyer takes a margin.

Safe removal

Working temperature: Iron 350–400 °C

Desolder at 350–400 °C or preheat and pull.

Hazards

☣ Beryllium oxide (BeO)

NEVER grind, sand, file, saw, drill, abrasive-cut, sandblast, hammer, crush, shred, torch, melt or incinerate anything that might contain BeO. Sell or dispose of suspect parts intact. Broken beryllium parts are worth nothing; your lungs are worth everything.

☠ Lead — dust more than fume

NEVER dry sweep or use compressed air on a scrapping bench. HEPA-vac or wet-wipe only.

Before you scrap it

Germanium types (2N404, AC128, OC44) sell to guitar-pedal builders for far more than metal value.

The common trap

Many gold-coloured TO-3 cans are gold flash over nickel. And power transistors use aluminium bond wire — no gold inside regardless of what the package looks like.

Questions

How much gold is in gold-plated hermetic transistors (to-3/to-5/to-18)?

Gold: 0.5–2 g/lb. At current spot that is about $157 of contained metal per pound.

How do you identify gold-plated hermetic transistors (to-3/to-5/to-18)?

A gold tint on the can AND the legs. Older military and industrial versions are gold-plated Kovar. Modern TO-220 and TO-247 plastic parts are worthless — epoxy, tinned steel and a copper or aluminium tab.

How do you remove gold-plated hermetic transistors (to-3/to-5/to-18) safely?

Desolder at 350–400 °C or preheat and pull.

Is gold-plated hermetic transistors (to-3/to-5/to-18) worth more working than as scrap?

Germanium types (2N404, AC128, OC44) sell to guitar-pedal builders for far more than metal value.

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