MICROSCRAPPINGE-waste field guide
Contacts & relays · Tier A

Aerospace Connectors & Backshells

Look at where the yellow actually is — on a mil connector the gold lives only on the tiny contact barrels, and a dull grey, olive-drab or yellow-iridescent shell is cadmium over aluminium: 80% of the weight is worth nothing, is illegal to torch, and must be de-populated before anyone will buy it.

Au 0.3–0.8 g/lb complete; ~3.6 g/lb de-populated contactsCu ~80 g/lbBase Backshells: ~0 g Au/lb
eBay typical$25–70per lb
Refiner pays$55per lb
Metal in it$66.1per lb at 4 Aug 2026 spot
Confidencemedof the yield figures

How to spot it

Circular bayonet or threaded shells (MIL-DTL-38999 I/II/III, 5015, 26482, 83723) or rectangular racks (ARINC 404/600, MIL-DTL-24308 D-subs) with removable crimp contacts in sizes 22D/20/16/12/8/4. Backshells are cylindrical adapters with strain-relief clamps or 45°/90° elbows. Part numbers read like D38999/26WD35SN; finish codes matter — W = olive-drab cadmium, F = electroless nickel, Z/M = zinc-nickel or black anodize. From Amphenol, Souriau, ITT Cannon, Glenair, Deutsch and Positronic.

Metal content

MetalQuantityNotes
Gold0.3–0.8 g/lb complete; ~3.6 g/lb de-populated contactsASTM B488 / SAE-AS39029: 50 µin Au min over 50 µin Ni. 100 µin space-grade doubles it to ~7 g/lb
Copper~80 g/lbBrass, BeCu and phosphor bronze contact base, 0.85–0.95 lb per lb of contacts
Base metalBackshells: ~0 g Au/lbCadmium, nickel or zinc-nickel plated Al/SS — the yellow is chromate, not gold

At 4 Aug 2026 spot prices that works out to $66.1 per pound of contained metal — Gold 0.5 g = $65.3, Copper 80 g = $0.86. A refiner paying $55 returns about 83% of that, which is normal: refining costs money and the buyer takes a margin.

Safe removal

Working temperature: No heat on shells; contact stripping is chemical

Use the correct colour-coded plastic M81969 removal tool: insert from the mating face, push to release the retention clip, withdraw from the rear. For bulk, shear the connector apart and dissolve or burn the silicone/fluorosilicone insert. Strip contacts in a sulphuric cell or dilute aqua regia after cutting off the wire barrels. Never torch cadmium-plated shells.

Hazards

☠ Cadmium

NEVER grind, burn, torch or braze cadmium-plated or AgCdO material, and don't inhale the black contact dust.

☣ Beryllium copper

NEVER put BeCu in a grinder, a sandblaster, or a melt.

☢ Radioactive materials

NEVER grind, sand, saw or incinerate anything that might contain thorium or radium. Sealed sources stay sealed.

☠ Lead — dust more than fume

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

🧪 Automotive & battery fluids

NEVER pour any of these down a drain or onto the ground. They are all regulated waste streams.

Before you scrap it

Very large — 5–50×. A D38999 that scraps for $2 sells for $25–200 used and $60–500 new, to aviation MRO, restoration, motorsport and marine buyers. Any connector with a legible part number, undamaged threads and intact insert should be sold as a part. Backshells: sell intact always, they have zero scrap value and $10–120 resale.

The common trap

Two dominant myths. Gold-plated backshells — backshells are almost never gold-plated; the gold look is cadmium's yellow chromate iridescence, and people buy them by the pound expecting gold. And weighing the whole connector: a 200 g shell-size-25 D38999 carries maybe 0.05–0.15 g of gold on 170 g of aluminium. The 1–2 g Au per pound figures on forums are true only for de-populated contacts, which are 15–25% of connector mass.

Questions

How much gold is in aerospace connectors & backshells?

Gold: 0.3–0.8 g/lb complete; ~3.6 g/lb de-populated contacts. Copper: ~80 g/lb. At current spot that is about $66.1 of contained metal per pound.

How do you identify aerospace connectors & backshells?

Look at where the yellow actually is — on a mil connector the gold lives only on the tiny contact barrels , and a dull grey, olive-drab or yellow-iridescent shell is cadmium over aluminium: 80% of the weight is worth nothing, is illegal to torch, and must be de-populated before anyone will buy it.

How do you remove aerospace connectors & backshells safely?

Use the correct colour-coded plastic M81969 removal tool: insert from the mating face, push to release the retention clip, withdraw from the rear. For bulk, shear the connector apart and dissolve or burn the silicone/fluorosilicone insert. Strip contacts in a sulphuric cell or dilute aqua regia after cutting off the wire barrels. Never torch cadmium-plated shells.

Is aerospace connectors & backshells worth more working than as scrap?

Very large — 5–50×. A D38999 that scraps for $2 sells for $25–200 used and $60–500 new, to aviation MRO, restoration, motorsport and marine buyers. Any connector with a legible part number, undamaged threads and intact insert should be sold as a part. Backshells: sell intact always, they have zero scrap value and $10–120 resale.

Related in Contacts & relays

Get this offline → The full guide runs in your browser with no signal, and you can add your own photos.