Chromel

Chromel is an alloy made of approximately 90 percent nickel and 10 percent chromium that is used to make the positive conductors of ANSI Type E (chromel-constantan) and K (chromel-alumel) thermocouples. It can be used up to 1100 °C in oxidizing atmospheres. Chromel is a registered trademark of the Hoskins Manufacturing Company.

Characteristics and properties of chromel (90%-10% Ni-Cr)

CHARACTERISTICS:
Temperature coefficient	0.00032 K−1
Electrical resistivity	0.706 µΩ m
Mechanical properties
Elongation at break	<44%
Izod impact strength	108 J m−1
Modulus of elasticity	186 GPa
Tensile strength	620–780 MPa
Physical properties
Density	8.5 g cm−3
Melting point	1420 °C
Thermal properties
Coefficient of thermal expansion	12.8×10−6 K−1 at 20–1000 °C
Maximum use temperature in air	1100 °C
Thermal conductivity	19 W m−1 K−1 at 23 °C

Chromel A

Chromel A is an alloy containing 80% of nickel and 20% chromium (by weight). It is used for its excellent resistance to high-temperature corrosion and oxidation. It is also commonly called Nichrome 80-20 and used for electric heating elements.

Chromel C

Chromel C is an alloy containing 60% nickel, 16% chromium, and 24% iron. It is also commonly called Nichrome 60 and is used for heating elements, resistance windings, and hot wire cutters.

External links

• Materials properties of thermocouple wires sold by Omega Engineering, Inc.
• Technical information on alloys at Electrovek-Steel Ltd.