C110 (Cu-ETP)
Electrolytic tough pitch (ETP) copper
Typical values for the temper in the title
C110 (Cu-ETP) is the most common copper: at least 99.90% copper, with about 200–400 ppm oxygen as copper oxide. Its electrical and thermal conductivity are very high (about 100% IACS), and it is ductile, formable and easy to solder.
It is the basic material for busbars, cables and conductors, heat exchangers and roofing. Its main limitation is the oxygen: heated in a hydrogen atmosphere, it embrittles.
Mechanical and physical properties
| Property | Value | Note |
|---|---|---|
| Tensile strength Rm | 220–275 MPa | |
| Yield strength Rp0.2 | 70–145 MPa | |
| Elongation A | 25–50% | |
| Hardness | 40–90 HB | |
| Modulus of elasticity E | 120 GPa | |
| Density ρ | 8.96 g/cm³ | |
| Electrical conductivity | about 100% IACS (annealed) | per MWS data |
| Machinability | 20% | relative rating in the site database |
Chemical composition (wt %)
| Element | Range | Role |
|---|---|---|
| Cu copper (incl. Ag) | min 99.90 | conductivity |
| O oxygen | about 0.02–0.04 (200–400 ppm) | as Cu2O |
Per ASTM B124 and copper.org data.
Tempers and heat treatment
Ordinary copper and brass are not hardened by heat treatment. Strength comes from cold work, marked as the temper: annealed (O) is soft, up to "hard" (H) is strong. Annealing returns the material to the soft condition.
| Condition | Properties | When to choose it |
|---|---|---|
| Annealed (O) | soft and ductile, lowest strength in the range | deep drawing and bending |
| Half hard (H02) | medium strength | general parts |
| Hard (H04 and up) | high strength, low ductility | springs and contacts |
Applications
- Busbars and conductors
- Cables and wires
- Heat exchangers
- Roofing and cladding
- Formed parts
Fabrication
Hydrogen embrittlement
Heated above about 400 °C in a hydrogen-bearing atmosphere, hydrogen reacts with the oxide to form steam at the grain boundaries, and the material cracks. For brazing or annealing in hydrogen, use oxygen-free copper (C101 or C102).
Machining
Difficult: pure copper is soft and "gummy". Sharp tools with a large positive rake.
Joining
Soldered and brazed easily. In welding, the high thermal conductivity requires preheat.
Compared with similar materials
| Material | Rm / Rp0.2 | Welding | When it is the better choice |
|---|---|---|---|
| C101 (Cu-OFE) | 220 / 70 MPa | Good (TIG) | oxygen-free, for hydrogen brazing and vacuum · material page |
| GlidCop AL-15 | 440 / 400 MPa | Electron beam | strengthened copper, keeps strength after heat · material page |
| C17200 (CuBe2) | 1380 / 1190 MPa | Electron beam / laser | strong beryllium copper, low conductivity · material page |
Common mistakes
Brazing C110 in a hydrogen furnace
The material embrittles and cracks. Use oxygen-free copper.
Machining with dull tools
The material smears, damaging finish and dimensions.
Ordering just "copper" without a grade
ETP, OF and DHP differ in hot behavior and conductivity.
Equivalents, standards and supply
| EN | CW004A |
|---|---|
| DIN | E-Cu58 |
| JIS | C1100 |
| Standards | ASTM B152 / EN 1652 / ISO 197 |
| Forms | plate · strip · wire · rod |
| Producers | Aurubis · Wieland · Mitsubishi Materials |
Learn more
Values are typical and for comparison only. For design, rely on the standard and the mill certificate. Sources: Copper Development Association (copper.org), ASTM B111 and B124, producer data sheets, and the METAL HUB materials database.
Updated: October 31, 2026