C10200 and Its Place in the Oxygen Free Copper Family
C10200 is an oxygen free copper with a maximum oxygen content of 0.0010 %. Removing the oxygen means the metal cannot form steam pockets at grain boundaries when it is heated in a reducing atmosphere, so it can be annealed, brazed and welded without the risk of hydrogen embrittlement that affects tough pitch copper. That single property is the reason the grade is used for vacuum components, electronic parts, refrigeration tube and any assembly where the joint has to remain gas tight.
Equivalent Designation Table
| Standard system | Designation | Region |
|---|---|---|
| GB | TU1 | China |
| EN | Cu-OF | Europe |
| UNS | C10200 | United States |
| DIN CEN/TS 13388 | CW008A | Germany |
| JIS | C1020 | Japan |
| BS | C102 | United Kingdom |
The wider conversion chart also includes the oxygen free electronic grade and the higher purity oxygen free grades. In the Chinese system TU0 and TU1 sit at the top of the oxygen free range, in the American system C10100 is the oxygen free electronic grade and C10200 the general oxygen free grade, and in the European and Japanese systems the corresponding entries are Cu-OFe and C103 on the one hand and the OF-Cu2 and C1010 / C1020 designations on the other. Because the oxygen limit, rather than the copper minimum alone, defines these grades, an order should always state the oxygen limit as well as the copper content.
Chemical Composition of C10200
ASTM B152 requires a minimum of 99.95 % copper and a maximum oxygen content of 0.0010 %, with the total of all other elements not exceeding 0.05 %. Individual residual elements are held at the levels below, which is what preserves both conductivity and ductility.
| Element | Sb | P | Bi | Ni | Fe | Pb | Sn | S | Zn |
|---|---|---|---|---|---|---|---|---|---|
| Maximum, % | 0.002 | 0.002 | 0.001 | 0.002 | 0.004 | 0.003 | 0.002 | 0.004 | 0.003 |
Every one of those elements is a conductivity killer if it is allowed to rise, and antimony, arsenic and phosphorus are the most damaging of all. Holding them at the levels shown keeps electrical conductivity at about 101 % IACS and thermal conductivity near 391 W/(m·K) while the metal retains the ductility needed for rolling, drawing, stamping and forging.
How C10200 Differs from C10100
| Description | C10200 | C10100 |
|---|---|---|
| Copper content | 99.95 % minimum | 99.99 % minimum |
| Certification | Certification as oxygen free is not mandatory | Certified as oxygen free electronic grade |
| Category | Oxygen free copper | Oxygen free electronic copper |
| Relative cost | Lower | Higher |
| Conductivity | High, about 101 % IACS | Higher purity, maximum commercial conductivity |
| Mechanical properties | Better strength for the same temper | Lower strength for the same temper |
The practical consequence is a cost and performance trade off. C10100 is specified where the very highest purity and the strictest certification are required, such as semiconductor, vacuum and high frequency components. C10200 is specified where oxygen free behaviour and high conductivity are required but the additional purity of the electronic grade would not change the performance of the part, which covers the large majority of heat exchanger, bus bar, tube and general electrical work.
Ordering Notes and Supply Forms
C10200 is supplied as tube and pipe, plate, sheet, strip, bar, rod, wire, coil, profile, bus bar and fittings, with dimensions and tempers produced to order. A purchase specification should state the designation in the buyer's own system, the oxygen limit, the required temper or mechanical property range, the dimensions with tolerances and the required certification. Where a buyer's drawing quotes TU1, Cu-OF, CW008A, C1020 or C102, the same material can be supplied and the certificate issued against the corresponding system so that the documents match the drawing. Inspection covers spectrometer analysis with a specific check on oxygen, conductivity measurement, tensile and hardness testing, dimensional verification and surface inspection, and certificates are issued for each heat. Packing is arranged for sea, air and courier shipment with protective film and wooden cases or strapped bundles.
Frequently Asked Questions
Q: What is the Chinese equivalent of C10200?
A: TU1 in GB/T 5231 is the matching Chinese designation for C10200 oxygen free copper. TU0 corresponds to the higher purity grade associated with C10100.
Q: Is Cu-OF the same as C10200?
A: Yes, Cu-OF is the European designation for the oxygen free copper with a maximum oxygen content of 0.0010 %, and the material number in DIN CEN/TS 13388 is CW008A.
Q: Why does the oxygen limit matter more than the copper minimum?
A: Oxygen forms cuprous oxide particles that react with hydrogen at high temperature and crack the metal. Keeping oxygen at or below 0.0010 % removes that failure mode, which is the defining property of the whole oxygen free family.
Q: Which is better, C10200 or C10100?
A: C10100 is purer and certified as oxygen free electronic grade, so it is chosen for the most demanding electronic and vacuum work. C10200 is less expensive, has slightly better mechanical properties and is adequate for almost all tube, bus bar and heat transfer applications.
Q: What conductivity can be expected?
A: About 101 % IACS in the annealed condition, which corresponds to a volume conductivity near 58.6 MS/m and a resistivity of about 1.724 µΩ·cm.
Q: What forms are supplied?
A: Tube, pipe, plate, sheet, strip, bar, rod, wire, coil, profile, bus bar and fittings, with chemical, conductivity and mechanical certification for each heat.
