// MATERIALS — TELLURIUM COPPER (C14500)
Tellurium Copper Machining
The copper that actually machines. C14500 keeps the conductivity your design needs and gives up the fight at the spindle — and it’s one of our specialties.
Pure copper is a wonderful conductor and a miserable machining material — gummy, grabby, and allergic to tight tolerances. Tellurium copper (C14500) fixes that: a half-percent of tellurium turns copper into a free-machining alloy while keeping roughly 90% of its conductivity. We run a lot of it, and it’s become one of the shop’s quiet specialties.
Why tellurium copper
When a part needs copper’s electrical or thermal performance and machined precision — threads, seal faces, bores, tight flatness — C14500 is usually the right answer. It cuts cleanly where C110 smears, holds finishes plating loves, and machines economically enough to make copper parts practical in production, not just in prototypes.
- ~90% of pure copper’s conductivity, with free-machining behavior
- Crisp threads, sharp shoulders, and fine surface finishes copper can’t normally give you
- Practical for production quantities — quoted by the part
- Full material certs and lot traceability, as with all our controlled work
What we make from it
Typical tellurium copper work through our shop: RF and microwave component bodies, connector and contact hardware, resistance-welding electrodes and tips, EDM electrode holders, heat sinks and thermal spreaders, and bus and electrical distribution components — often headed to electronics, semiconductor-equipment, and defense programs.
Machining it well
Free-machining doesn’t mean carefree. Copper alloys are soft enough to deform under clamping, conductive enough to pull heat into the tool, and burr-prone at every edge. Running them well is about sharp tooling, deliberate workholding, chip control, and edge management — the craft that separates a copper part that gauges from one that just looks shiny. Our in-house inspection closes the loop on every lot.
Finishing & plating
Copper parts usually ship finished: tin plating for solderability, electroless nickel for wear and corrosion protection, or barrel plating when the run is high-quantity small parts. We machine with the plating spec in mind so the finished dimension — not the bare one — is what hits the print.
Copper, brass & bronze
C14500 headlines the family, but the whole yellow-metals shelf runs through the shop: C110 when the print demands pure copper, C360 free-machining brass for fittings and hardware, and bearing bronzes. If it’s copper-colored and needs to hold a tolerance, send the drawing.
| Specialty alloy | C14500 tellurium copper (C145) |
|---|---|
| Also machined | C110 copper · C360 brass · bearing bronzes |
| Typical parts | RF/connector bodies, welding electrodes, EDM holders, thermal hardware, bus components |
| Finishing | Tin plating · electroless nickel · barrel plating for volume runs |
| Volumes | Single prototypes through documented production |
| Compliance | ISO 9001:2015 · ITAR registered · SDVOSB-certified |
// FAQ
Frequently asked questions
C14500 is copper with a small tellurium addition (about half a percent) that transforms how it machines. It keeps roughly 90% of pure copper’s electrical and thermal conductivity while cutting cleanly — which is why it’s the standard choice when a conductive part also has real geometry and real tolerances.
We do when a print demands it — but pure copper is gummy, work-hardens, tears instead of cutting, and fights every tolerance. If your application allows C14500, you get nearly the same conductivity with far better surface finishes, tighter achievable tolerances, and lower part cost.
Yes — copper parts commonly leave here tin-plated or electroless-nickel plated for solderability and corrosion protection, through our finishing services. We machine with plating in mind: clean surfaces, controlled burrs, and dimensions that account for plating thickness.
Yes — the whole yellow-metals family: C360 free-machining brass, bronzes, and other copper alloys, from single prototypes to production runs, quoted by the part.
Got a tough part? Send it over.
Upload your drawing or STEP file and we'll come back with pricing and lead time — from a single high-mix part to full production runs, held to exacting tolerances.