Nichrome Alloy Wire

Technical Information on Nichrome Wire

Nichrome is a non-magnetic alloy of nickel, chromium, and often iron, usually used as a resistance wire.

Patented in 1905, it is the oldest documented form of resistance heating alloy. A common alloy is 80% nickel and 20% chromium, by mass, but there are many others to accommodate various applications. It is silvery-grey in colour, is corrosion-resistant, and has a high melting point of about 1,400 °C (2,550 °F). Due to its resistance to oxidation and stability at high temperatures, it is widely used in electric heating elements, such as in appliances and tools. Typically, nichrome is wound in coils to a certain electrical resistance, and current is passed through it to produce heat.

Uses:

Nichrome is used in the explosives and fireworks industry as a bridgewire in electric ignition systems, such as electric matches and model rocket igniters.

Industrial and hobby hot-wire foam cutters use nichrome wire.

Nichrome wire is commonly used in ceramic as an internal support structure to help some elements of clay sculptures hold their shape while they are still soft. Nichrome wire is used for its ability to withstand the high temperatures that occur when clay work is fired in a kiln.

Nichrome wire can be used as an alternative to platinum wire for flame testing by colouring the non-luminous part of a flame to detect cations such as sodium, potassium, copper, calcium etc.

The alloy tends to be expensive due to its high nickel content. Distributor pricing is typically indexed to commodity market prices for nickel.

Other areas of usage include motorcycle silencers, in certain areas in the microbiological lab apparatus, and as the heating element of plastic extruders by the RepRap 3D printing community.

For heating, resistance wire must be stable in air when hot. Nichrome wire forms a protective layer of chromium oxide.

Nichrome may be also used as the coils of electronic cigarettes for vaping.

The properties of nichrome vary depending on its alloy. Figures given are representative of typical material and are accurate to expressed significant figures. Any variations are due to different percentages of nickel or chromium.

Material property Value Unit
Modulus of elasticity 2.2 × 1011 Pa
Density 8400 kg/m3
Melting point 1400 °C
Electrical resistivity at room temperature (1.0—1.5) × 10−6 Ω·m
Specific heat 450 J/(kg·K)
Thermal conductivity 11.3 W/(m·K)
Thermal expansion 14 × 10−6 K−1
Standard ambient temperature and pressure
used unless otherwise noted.

Table 2: Current (A) vs. temperature characteristics, straight wire.

Showing approximate current (in amperes) necessary to produce a given temperature. Applying only to straight wires stretched horizontally in free air. Values for diameters from 0.040" through 0.010" are based on coiling on an arbor 0.12" diameter and stretched to twice the close-wound lengths.

Wire Gauge
(B&S No. / AWG)
Diam. (inches) 400 °F
204 °C
600 °F
316 °C
800 °F
427 °C
1000 °F
538 °C
1200 °F
649 °C
1400 °F
760 °C
1600 °F
871 °C
1800 °F
982 °C
2000 °F
1093 °C
12 0.081 11.34 15.91 20.27 25.53 31.77 39.03 46.73 54.80 63.01
13 0.072 9.73 13.53 17.21 21.61 26.89 33.06 39.60 46.41 53.31
14 0.064 8.34 10.50 14.59 18.30 22.76 28.01 33.56 39.31 45.11
15 0.057 7.15 9.78 12.38 15.50 19.26 23.73 28.44 33.30 38.17
16 0.051 6.13 8.31 10.50 13.11 16.30 20.10 24.10 28.20 32.30
17 0.045 5.31 7.18 9.13 11.30 13.90 16.90 20.30 23.60 27.00
18 0.040 4.66 6.26 7.90 9.75 11.96 14.51 17.37 20.48 23.08
19 0.036 4.09 5.46 6.84 8.41 10.30 12.45 14.87 17.78 19.73
20 0.032 3.58 4.77 5.92 7.25 8.86 10.69 12.72 15.43 16.87
21 0.0285 3.14 4.16 5.13 6.26 7.63 9.17 10.88 13.40 14.40
22 0.0253 2.76 3.63 4.44 5.40 6.56 7.87 9.31 11.63 12.33
23 0.0226 2.42 3.16 3.84 4.67 5.65 6.76 7.97 10.09 10.54
24 0.020 2.12 2.76 3.32 4.01 4.86 5.80 6.82 8.76 9.01
25 0.0179 1.84 2.42 2.90 3.44 4.15 4.97 5.86 6.96 7.72
26 0.0159 1.58 2.09 2.52 3.00 3.61 4.31 5.06 5.97 6.63
27 0.0142 1.34 1.80 2.19 2.62 3.14 3.73 4.37 5.12 5.69
28 0.0126 1.18 1.55 1.90 2.28 2.73 3.23 3.77 4.39 4.88
29 0.0113 1.02 1.34 1.65 1.99 2.37 2.80 3.25 3.76 4.39
30 0.010 0.875 1.16 1.43 1.74 2.06 2.43 2.81 3.22 3.59

Nichrome 80/20 62/16 Data Table

Nichrome Ohms per Linear Ft. Chart

Nichrome Wire Material Safety Data Sheet

Nichrome Wire Amperage Chart

Nichrome Wire Resistance by AWG Size

Nichrome Wattage Chart

Nichrome Resistance Comparsion Chart

Resistance Alloy 675

Resistance Alloy 650

Nichrome 80/20 & 60/16 Ohms per Feet Chart

Resistance Alloy Technical Data

Nichrome 60/16 Composition Chart

Resisitance Alloy Ft per lb Conversions

Nichrome 80/20 Composition Chart

Nichrome Wire Quotation