Resistance Wire


Resistance wire is used to control the amount of current in a circuit. High resistivity is better since a shorter wire can then be used. When the stability of the resistor is of primary importance the alloy’s temperature coefficient of resistivity and corrosion resistance are very important in material selection. When it is used for heating elements for applications such as electric heaters and toasters, high resistivity and oxidation resistance is important.

Sometimes resistance wire is insulated by ceramic powder and sheathed in a tube of another alloy. Such heating elements are used in electric ovens and water heaters, and in specialized forms for cooktops.

Nichrome, a non-magnetic 80/20 alloy of nickel and chromium, is the most common resistance wire for heating purposes because it has a high resistivity and resistance to oxidation at high temperatures. When used as a heating element, it is usually wound into coils. One challenge when using nichrome wire is that common tin-based electrical solder will not bond with it, so the connections to the electrical power must be made using other methods such as crimp connectors or screw terminals.

If you have any questions or comments, please contact us.

Calculator tool

Enter the resistivity value (OHMS/CMF) of any alloy from the chart below into the RESISTIVITY cell (double click the cell to highlight/clear/input your selection). Enter the desired diameter of the wire into the DIAMETER cell and the calculator will give minimum and maximum resistance values for standard 5% range, and special order 3% range. All values are for 20C.

Properties of Major Alloys

MaterialChemical Composition (%)Resistivity at 20°CCoefficient of Linear Expansion
Tensile Strength
(KPSI at 20°C)
Specific GravityMagnetic AttractionApprox. Melting Point
OHMS/ CMFTCR (0-100°C)μm/m (0-100°C)Min.Max.(lb/in³)(°C)
MWS-87522.5 Cr, 5.5 AI, .5 Si, .1 C, bal. Fe8750.000020.0000121051750.2567.10Strong1,520
MWS-80075 Ni, 20 Cr, 2.5 AI, 2.5 Cu8000.000020.0000141002000.2938.10None1,350
MWS-67561 Ni, 15 Cr, bal. Fe 6750.000130.000014951750.2988.25Faint1,350
MWS-65080 Ni, 20 Cr6500.00010.0000131002000.3048.41None1,400
ALLOY 4242 Ni, bal. Fe3900.0010.000003701500.2958.10Strong1,425
MWS-29455 Cu, 45 Ni2940.000020*0.000015601350.3218.90None1,210
MWS-294R29 Ni, 17 Co, bal. Fe2940.00330.000003651500.3028.36Strong1,450
Manganin13 Mn, 4 Ni, bal. Cu2900.000015**0.00001940900.2968.19None1,020
Alloy 5250.5 Ni, bal. Fe2600.00290.000005701500.3018.25Strong1,425
MWS-18023 Ni., bal. Cu1800.000180.000016501000.3218.90None1,100
MWS-12070 Ni, 30 Fe1200.00450.000015701500.3058.46Strong1,425
MWS-9012 Ni, bal. Cu900.00040.00001635750.3218.90None1,100
MWS-606 Ni, bal. Cu600.00050.00001635700.3218.90None1,100
MWS-302 Ni, bal. Cu300.00130.00001730600.3218.90None1,100
Nickel 20599 Ni570.00480.000013601350.3218.90Strong1,450
Nickel 27099.97 Ni450.00670.00001348950.3218.89Strong1,452

*TCR at 25-105°
**TCR at 15-35°C
Note: Available bare or insulated. See the insulation guide.

Resistance Alloy Data

Download Data Sheet

Resistivity of some common materials

MaterialResistivity (OHM-CMIL/FT)Resistivity (10−6 OHM-CM)
Carbon (amorphous)233.95
Nichrome V650108.1
Stainless Steel (304)54190
Steel (.5% carbon)10016.62

Trade Name Cross Reference

MWS WireCarpenter Tech.Driver-HarrisHarrisonHoskinsJelliffKanthalMolecu
MWS - 875Alchrome 875-HAI-FeCr Al25Alloy 875-Kanthal A-1-
MWS - 800EvanohmKarmaHAI-431Chromel RAlloy 800Nikrothal LMoleculoy
MWS - 675Tophet CNichromeHAI-NiCr 60Chromel CAlloy CNikrothal 6Electroloy
MWS - 650Tophet ANichrome VHAI-NiCr 80Chromel AAlloy ANikrothal 8Protoly
MWS - 294CupronAdvanceHAI-CuNi 102CopelAlloy 45Cuprothal 294Neutroloy
MWS - 294RKovar-HAI-373----
MWS - 180180 AlloyMidohmHAI-180Alloy 380Alloy 180Cuprothal 180-
MWS - 120BalcoHytemoHAI-380-Alloy 120-Pelcoloy
MWS - 9090 Alloy#95 AlloyHAI-90Alloy 290Alloy 90Cuprothal 90-
MWS - 6060 AlloyLohmHAI-60Alloy 260Alloy 60Cuprothal 60-
MWS - 3030 Alloy#30 AlloyHAI-30Alloy 230Alloy 30Cuprothal 30-