Constantan: Constantan is a copper-nickel alloy. The amount of nickel in constantan is 40%.
Properties:
1. It is silver like appearance.
2. Its electrical resistivity is 5.2*10-8 ohm-m.
3. Its SPECIFIC gravity is 8.9.
4. Its melts at 1300 degree c.
5. The maximum permissible working temperature is about 500 degree c.
6. It can be drawn into thin wires.
7. It is highly corrosion resistant.
USES: It is used for making resistance elements for items like loading rheostats and starters for electric motors. It is also used in thermocouples.