Resistance Wire

MWS Wire / Resistance Wire

Resistance wire is primarily used as an electrical resistor. Resistance wires restrict the flow of current which converts electrical energy into heat. Beyond simple resistors, resistance wire is an essential component in many applications like RTD sensors, thermocouples, rheostats, voltage control relays, heating elements and potentiometers.  The key to selecting the perfect resistance wire is found in the unique properties of the wire based on the alloy used.

Factors to consider when choosing a Resistance wire.

Resistivity:

Resistivity is a fundamental parameter of resistance wire, which is determined based on electric flow that needs to be controlled or the amount of heat that the wire needs to generate.

Temperature Coefficient of Resistance (TCR):

When stability is critical, the alloy's TCR is an essential factor in material selection.

Corrosion and Oxidation Resistance:

An alloy's ability to withstand corrosion is critical, especially in harsh environments. Alloys with good oxidation resistance avoid oxide layers contaminating their surfaces and protect wire from thermal fatigue.

Geometry:

The shape of the wire is proportional to its resistance. MWS can produce round wire to resistance specifications and provide special shaped requirements.

Material (Alloys):

Refer to the table below for resistivity values by alloy.

Wire Resistance Calculator

Imperial Results

Wire Size

inches

Resistivity

Ω-Cir.mil/ft

Resistance (nom)

Ω/ft

±5% range (min)

Ω/ft

±5% range (max)

Ω/ft

±3% range (min)

Ω/ft

±3% range (max)

Ω/ft

Metric Results

Wire Size

mm

Resistivity

Ω-mm²/meter

Resistance (nom)

Ω/meter

±5% range (min)

Ω/meter

±5% range (max)

Ω/meter

±3% range (min)

Ω/meter

±3% range (max)

Ω/meter

Resistance Wire Data

MaterialResistivity
(Ω-Cir.mil/ft)(Ω-mm²/meter)
Aluminum170.0283
Brass (30Zn, 70Cu)370.0615
Constantan2940.4888
Copper10.3710.0172
Iron57.810.0961
Manganin2900.4821
Molybdenum32.120.0534
MWS 675 (Nichrome)6751.1221
MWS 650 (Nichrome V)6501.0806
Nickel 205570.0948
Nickel 270450.0748
Platinum63.910.1062
Stainless Steel 304433.10.7200
Stainless Steel 316444.60.7391

Cover image of the "Wired for your Success" Technical Data Book by MWS Wire Industries, showcasing equipment and their selection of specialty and magnet wire.

Resistance Wire Technical Data

Need more info about resistance wire? See the Data Sheet in our Tech Book.

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Product Spotlight

Resistance Wire

Chromium based Alloys (Heating wire)

MWS-650 | MWS-675 | MWS-800
MWS-875

Advantages:

  • High resistivity
  • Good oxidation resistance
  • High mechanical strength
  • Can operate at temperatures up to 2192°F

Applications:

  • Commonly used as heating elements in both domestic and industrial appliances
  • Widely used as tool wire in EDM machining for precise metal cutting
  • Hot wire cutting and sealing capabilities for foam, plastics and rubber

Available in: Annealed and Temper conditions per ASTM B344

Nickel-Iron based Alloys

MWS-42 | MWS-52 | MWS-120

Advantages:

  • Self-limiting heating wire, the resistance doubles at 482°F and reduces power at overheating
  • High coefficient of resistance (TCR)
  • Strong magnetic attraction

Applications:

  • Low temperature heating devices
  • Voltage regulator, sensors, temperature sensitive resistors, potentiometers, timing devices and temperature compensating devices
  • Measure flow of fluids at a certain flow rate range

Available in: Annealed and Temper conditions per ASTM F30

Nickel-Copper based Alloys

MWS-30 | MWS-60 | MWS-90
MWS-180 | MWS-294

Advantages:

  • Low resistance applications up to 750°F
  • Higher coefficient of resistance (TCR)
  • Good stability

Applications:

  • Thermocouples, RTD sensors
  • Wire wound precision resistors, rheostats, voltage control relays

Available in: Annealed and Temper conditions per ASTM B127

Pure-Nickel based Alloys

Nickel-200 | Nickel-205 | Nickel-270

Advantages:

  • Suitable for high temperatures up to 2600°F
  • Highly resistant to oxidation and corrosion
  • Strong magnetic attraction

Applications:

  • Medical devices
  • Magnetic transducers, lead wires
  • Fire protection systems in aircrafts

Available in: Annealed and Temper conditions per ASTM F1, F2, F3

Others

MWS-294R | Manganin | Inconel*

Advantages:

  • Low temperature coefficient of resistance (TCR)
  • Suitable for low temperature applications

Applications:

  • Electrical conductor in Cryogenic, sensors, medical devices
  • Hermetic glass-to-metal sealing

Available in: Annealed and Temper conditions per ASTM B127 (MWS-294R) and ASTM B267 (Manganin)

*For more info on Inconel wire, refer to our Mechanical Alloys page.

Special Processes

Wire is available in sizes 14 – 44 AWG with the following options:

  • Soft/Hard Temper
  • Bare
  • Insulated
  • Shaped
  • Plated
  • Bondable
  • Can be made to resistance
  • Laser ablated reel-to-reel
  • Discrete lengths cut to size

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-

*All trademarks are the property of their respective owners

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