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What is Resistance Wire?

Shannon Kietzman
Shannon Kietzman

Resistance wire is a type of alloy with several uses, with some types being made from a range of alloys. This material receives its name because it works as a heating element and performs as a heating wire. As such, it is able to resist all flow of electricity, as well as the heat produced from electrical energy. In addition to repelling heat, resistance wire is resistant to corrosion.

This material is generally found packaged in a plastic bag and is available in a variety of lengths, including 25, 50, 75 and 100 feet (7.62, 15.24, 22.86, and 30.48 meters). Some resistance wire, however, is available on reels, in drum packs, and even on coils, which are generally used for larger sizes and lengths of wire.

A multimeter, which can be used to measure resistance.
A multimeter, which can be used to measure resistance.

As a rule, all resistance wire must meet BS 115 requirements. This means that it must meet the specifications for all metallic resistance materials intended for electrical use. If, however, the wire has a diameter of less than 0.32 mm, it must meet BS 1117 requirements, which are set forth for bare and fine resistance wire used for electrical equipment.

Nichrome is a well-known form of resistance wire. It is used to resist heat created from certain jobs, such as foam cutting and working with polyurethane and certain fabrics. There are also some forms of this material that contain strong heating elements appropriate for industrial heating, process heating, and customized heating. These are ideal for use in kilns.

The temperature of operation when using resistance wire usually becomes a factor when the material being used and the atmospheric temperature are both taken into consideration. Therefore, each is considered when creating a new element design. The temperature can also change with the resistance of the metal. For these reasons, there are temperature calculators available in stores where this material is sold. There are also operation conditions available with the appropriate equations for determining the proper resistance wire to use for a specific job.

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Discussion Comments


@MrMoody - There are a number of applications actually. I have a clothes iron and I think it uses the same concept. I wouldn’t be surprised if it used insulated resistance wire made out of nichrome.

Since you mention the concept of a release mechanism for a toaster, I think the same thing applies for my clothes iron. It has an automatic shut off feature after a certain time.

Perhaps it measures the temperature of the resistance wire and if it’s too hot, it assumes the iron has been on and out of use for too long. Then it shuts it down. This is a great feature to have, because I tend to be a bit absent minded and on a few occasions have left the iron on all day. It’s nice to come home from work and see that the house hasn’t burned down.


You can find a lot of appliances that have these wires. Just look at your toaster oven. It has a high resistance wire (a bunch of them actually).

The wires heat up in response to the electric current and that’s what warms up your toast. The older toaster ovens had an added special feature. When they got to a certain temperature they would pop the toast right out of the oven and then shut down.

The oven I have now doesn’t do that. Maybe some of the newer toaster ovens out there still do that, I don’t know. But it sure was convenient.


I recently took apart a little USB powered heater. There are solid copper wires from the USB port to the heating element. The actual heating element wasn't actually a solid wire like I thought it would be, but rather a hundred or so hair sized filaments (silver/grey in color and soft to the touch) packed together. Any idea what this material is or might be called? Or the advantages/disadvantages? Thanks!


how much current can carry 2.5 copper cable? and how to calculate?

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    • A multimeter, which can be used to measure resistance.
      By: pokchu
      A multimeter, which can be used to measure resistance.