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 at temperatures up to 1100 °C in oxidizing atmospheres. Chromel is a registered trademark of Concept Alloys, Inc.
|Temperature coefficient||0.00032 K−1|
|Electrical resistivity||0.706 µΩ m|
|Elongation at break||<44%|
|Izod impact strength||108 J m−1|
|Modulus of elasticity||186 GPa|
|Tensile strength||620–780 MPa|
|Density||8.5 g cm−3|
|Melting point||1420 °C|
|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 is an alloy containing approximately 80% of nickel and 20% chromium (by weight). More precisely, Cr 20%, Fe 0.5%, Si 1%, Ni remainder  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 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.
Chromel R has a composition of Cr 20%, Ni 80%.
Chromel-R was also produced as a woven fabric of chromel wires. It was developed by Litton Industries for use by NASA in the Apollo program. Patches of Chromel-R formed an outer layer of the spacesuit where abrasion resistance was needed. These patches can be seen as silver-grey areas over the white Beta cloth of the main suit. The upper areas of the overshoes, the gloves and patches beneath the life support backpack were of Chromel-R.
- Concept Alloys, Inc. Intellectual Property retrieved 12 April 2016
- John P. Frick, ed. (2000). Woldman's Engineering Alloys. ASM International. p. 264. ISBN 9780871706911.
- Schneiderman, Deborah; Winton, Alexa Griffith (2016). Textile Technology and Design. Bloomsbury Publishing. p. 177. ISBN 9781474261968.
- "New Apollo is to have fireproof cabin materials and spacesuits". Popular Science. November 1967. p. 98.
- "Apollo Experience Report - Development of the Extra Vehicular Mobility Unit" (PDF), NASA Technical Note, NASA, p. 12, November 1975, NASA TN D-8093
- Materials properties of thermocouple wires sold by Omega Engineering, Inc.
- Technical information on alloys at Electrovek-Steel Ltd.
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