C10200 Oxygen-Free Copper Tubing at a Glance
UNS C10200 is a high-purity oxygen-free copper that is widely supplied as seamless tubing for heat transfer, electrical and vacuum service. Its copper content is 99.95 percent minimum, its oxygen content is controlled below about 0.001 percent, and other residual elements such as phosphorus and sulphur are restricted, so the metal remains clean and predictable through forming, brazing and long-term operation.
Because there is virtually no oxygen in the metal, the tubing does not embrittle when it is brazed in a hydrogen-bearing or reducing atmosphere, and it does not release gas in vacuum service. Those characteristics, together with a thermal conductivity of roughly 390 W/(m·K), explain why the grade appears in condensers, electronic cooling circuits and analytical instruments.
Composition and Product Forms
| Item | Requirement or range |
|---|---|
| Copper (Cu), including silver | 99.95 % minimum |
| Oxygen (O) | 0.001 % maximum |
| Total other elements | 0.05 % maximum |
| Standard | ASTM B111/B111M; ASME SB111 |
| Outside diameter | typically 4 mm to 108 mm |
| Wall thickness | typically 0.5 mm to 5 mm |
| Lengths | straight 3 m, 6 m, 12 m, or coils and U-bends to order |
| Tempers | O60 soft annealed; drawn tempers for straight tube |
Key Properties
The grade is chosen for two things above all: conductivity and formability. Electrical conductivity is about 101 percent IACS, the highest of the common wrought coppers, and thermal conductivity follows at roughly 390 W/(m·K). Soft annealed tubing reaches a tensile strength of 200-250 MPa with at least 35 percent elongation, so it bends and expands without cracking, while drawn tempers raise strength into the 300-400 MPa band when stiffness is the priority.
| Property | Typical value |
|---|---|
| Electrical conductivity | about 101 % IACS |
| Thermal conductivity | about 390 W/(m·K) |
| Tensile strength, annealed | 200-250 MPa |
| Tensile strength, drawn | 300-400 MPa |
| Elongation, annealed | 35 % minimum |
| Density | 8.94 g/cm³ |
Applications
Condensers, evaporators, oil coolers and other shell-and-tube exchangers.
Electronics cooling plates, cold plates and heat sinks for power devices.
Vacuum chambers, accelerator hardware and space-qualified assemblies.
Induction heating coils and high-temperature furnace components.
Precision instruments, waveguides and superconducting magnet supports.
Forming, Joining and Heat Treatment
Cold forming is the normal fabrication route: the tube is cut, deburred, bent, expanded into tube sheets and sometimes swaged at the ends. A full anneal at 250 °C to 650 °C is used after heavy cold work, and a stress relief at 200 °C to 250 °C is applied when dimensional stability matters. Hot working, where used, is carried out between about 750 °C and 950 °C.
Soldering and brazing are rated excellent for this grade, and brazing in reducing atmospheres is straightforward because no oxide layer forms under the joint. Gas tungsten arc welding with matching filler and clean, dry shielding gas gives sound welds with low porosity. All fabrication areas should be kept free of lead, bismuth and low-melting alloys, which embrittle copper grain boundaries if they contaminate the surface.
Inspection and Handling Notes
Eddy-current testing and dimensional inspection are performed on the finished tube, and pressure testing can be hydrostatic or pneumatic to the agreed test pressure.
Expansion and flattening tests confirm ductility before the tube is rolled into a tube sheet.
Grain size is checked in the annealed condition, because a fine uniform grain structure is the best guarantee of consistent bending behaviour.
Store tubing dry and capped. Sea transport without adequate packing causes surface tarnish and, in chloride-rich conditions, pitting.
FAQ
Q: Which standard covers C10200 tubing?
Seamless condenser and heat exchanger tubing is supplied to ASTM B111/B111M, which is technically identical to ASME SB111. Bright annealed tube of the same composition is covered by ASTM B68, and general copper tube by ASTM B75.
Q: Does C10200 tubing contain phosphorus?
No phosphorus is deliberately added. Only trace residuals are permitted, which is why the grade holds about 101 percent IACS conductivity instead of the 70-90 percent IACS typical of phosphorus-deoxidised C12200.
Q: Can the tubing be bent to a tight radius?
Yes, in the soft annealed temper. Bending on a mandrel with a radius of about one and a half to two times the outside diameter is normal practice, and the wall thickness on the outside of the bend should be checked afterwards.
Q: Why does oxygen content matter for vacuum service?
Oxygen-bearing copper releases gas and can form internal voids at high temperature. C10200 with oxygen below 0.001 percent keeps outgassing low and avoids hydrogen embrittlement when parts are brazed or baked out.
Q: Is a protective finish needed?
In dry indoor service, no. In humid or sulphur-bearing environments, a light oil film, tinning or nickel plating prevents tarnish and keeps contact resistance stable on electrical parts.
Q: What documentation is issued with the tubing?
Mill certificates report the heat analysis and mechanical properties, and test records for eddy current, pressure or expansion testing are issued on request so that the material can be traced from heat to installation.
