Technical overview
Commercial copper is supplied in distinct grades. Electrolytic tough pitch (ETP, C11000) is the general-purpose conductor grade with a minimum of 100% IACS when annealed. It contains oxygen, which can cause hydrogen embrittlement if the copper is brazed or welded in a reducing atmosphere.
Oxygen-free grades remove that risk. C10200 (OF) limits oxygen to 0.0010%, and C10100 (OFE, oxygen-free electronic) is the highest-purity grade at ≥ 99.99% copper with tightly limited impurities and a 101% IACS minimum. OFE is specified for vacuum seals, microwave tubes, waveguides and other electron-device parts.
Phosphorus-deoxidised copper (DHP, C12200) trades some conductivity (85% IACS) for excellent brazeability and is the usual grade for tube and heat-exchanger work.
Grades & standards
Grades are distinct materials — properties and uses below apply to the named grade only.
C10100
Oxygen-Free Electronic (OFE)
Composition: Cu ≥ 99.99% (excl. Ag), O ≤ 0.0005%, individual impurity limits in ppm
- Min. 101% IACS (annealed)
- Will not hydrogen-embrittle during brazing or welding
- Electron devices, vacuum seals, waveguides, klystrons
Listed specifications: ASTM F68 · ASTM B152/B152M · ASTM B187/B187M · ASTM B170
C10200
Oxygen-Free (OF)
Composition: Cu ≥ 99.95% (incl. Ag), O ≤ 0.0010%
- High-conductivity copper (min. 100% IACS annealed)
- Busbars, coaxial cable, waveguides, glass-to-metal seals
Listed specifications: ASTM B152/B152M · ASTM B187/B187M · ASTM B170
C11000
Electrolytic Tough Pitch (ETP)
Composition: Cu ≥ 99.90% (incl. Ag); oxygen and trace elements vary with process
- Min. 100% IACS (annealed)
- Busbars, conductors, terminals, roofing
Listed specifications: ASTM B152/B152M · ASTM B187/B187M · ASTM B1 / B2 / B3 (wire)
C12200
Phosphorus-Deoxidised, High Residual P (DHP)
Composition: Cu ≥ 99.9%, P 0.015–0.040%
- 85% IACS
- Excellent brazeability
- Tubes for heat exchangers, condensers, gas and hydraulic lines
Listed specifications: ASTM B75/B75M · ASTM B88 · ASTM B111/B111M
Technical properties
| Property | Value | Applies to | Source |
|---|---|---|---|
| Electrical conductivity (min., annealed) | 101% IACS | C10100 OFE | Copper Development Association Inc. |
| Electrical conductivity (min., annealed) | 100% IACS | C11000 ETP | Copper Development Association Inc. |
| Electrical conductivity | 85% IACS | C12200 DHP | Copper Development Association Inc. |
| Melting point | 1083 °C | C10100 OFE | Copper Development Association Inc. |
| Specific gravity | 8.94 | C10100 OFE | Copper Development Association Inc. |
Typical or specified values for the named grade from the cited source. Actual values depend on temper, size and the producing mill — rely on the mill certificate for your lot.
Forms
Typical industry forms for this material. They are not a stock list — form, size and availability are confirmed per enquiry.
- Busbar & flat
- Rod
- Sheet, strip & plate
- Wire & wire rod
- Tube
- Foil
Applications & industries
- Busbars and bus conductors
- Electrical conductors, terminals and connectors
- Vacuum seals, microwave tubes and waveguides (OFE)
- Heat-exchanger and condenser tubes (DHP)
- Brazed and welded assemblies (oxygen-free grades)
Selection notes & limitations
- ETP (C11000) contains oxygen and can suffer hydrogen embrittlement if brazed or annealed in hydrogen-bearing atmospheres — specify an oxygen-free or deoxidised grade for those processes.
- DHP copper has lower conductivity (85% IACS) and is not a substitute for conductor grades.
What to specify when requesting a quote
- 1Minimum conductivity (% IACS) required
- 2Whether the part will be brazed, welded or used in vacuum (drives OF/OFE vs ETP)
- 3Grade and the standard it must conform to (ASTM, EN, IS, UNS or your drawing)
- 4Form and dimensions — thickness or diameter, width, length and tolerances
- 5Approximate quantity, and whether the requirement is one-off or recurring
- 6Intended application, so the grade can be cross-checked before quoting
- 7Documents required — e.g. mill test certificate, chemical analysis, certificate of conformity
- 8Delivery city / site and the date you need material by
Documents buyers may request
Mill test certificate
e.g. EN 10204 type 3.1 inspection certificate, where the producing mill issues one
Chemical analysis report
heat / lot composition against the specified grade
Certificate of conformity
confirming the material meets the ordered standard
Heat / lot traceability
heat numbers marked on material and documents
Dimensional inspection report
for cut-to-size or machined material
Safety Data Sheet (SDS)
especially for lead, beryllium-, cadmium- or lead-bearing products
Which documents can be provided depends on the source mill and is confirmed with each quotation.
Frequently asked questions
What is the difference between OF and OFE copper?
Both are oxygen-free. OFE (C10100) is the higher-purity grade — Cu ≥ 99.99% with individual impurity limits in parts per million and a 101% IACS minimum — and is specified for electron devices. OF (C10200) is Cu ≥ 99.95% with O ≤ 0.0010%.
When is ETP copper not suitable?
When the part will be brazed or heated in a hydrogen-bearing atmosphere. ETP contains oxygen and can embrittle; oxygen-free (C10100/C10200) or deoxidised (C12200) grades are used instead.
Can you supply OFE copper?
Availability of each grade, form and size is confirmed per enquiry. Share your grade, dimensions and quantity and we will confirm sourcing.
Sources & technical references
- C10100 — Oxygen-Free Electronic (OFE) (CDA alloy database) — Copper Development Association Inc. (CDA). Checked 2026-10-14.
- C10200 — Oxygen-Free (OF) (CDA alloy database) — Copper Development Association Inc. (CDA). Checked 2026-10-14.
- C11000 — Electrolytic Tough Pitch (ETP) (CDA alloy database) — Copper Development Association Inc. (CDA). Checked 2026-10-14.
- C12200 — Phosphorus-Deoxidized, High Residual P (DHP) (CDA alloy database) — Copper Development Association Inc. (CDA). Checked 2026-10-14.
