Resistance Wire is a particular category of wire used predominantly in applications that require the conversion of electricity into heat.
There is a fairly broad spectrum of applications across a number of sectors, from domestic appliances and commercial use, right through to higher-intensity industrial applications.
For example, in the domestic appliances sector resistance wire is used to create heat in hair dryers, electric heaters, hand dryers, toasters, electric ovens, electric thermos and more.
Commercially, resistance wire is used to create the coils that generate heat in heated seats, circuits that require resistors to manage the amount of current that flows through them,
Desirable properties of Resistance Wire
The primary purpose of resistance wire is to conduct electricity and produce stable, measurable heat and resistance as part of a larger application.
Oftentimes these applications are in high-corrosion or exothermic devices, thus, the most desirable qualities for resistance wire are high resistivity and high resistance to oxidation. To assist with the latter in particular, sometimes resistance wire is insulated in ceramic powder and sheathed in the tube of another alloy.
Types of Resistance Wire
There are various types of resistance wire, each of which brings unique properties and advantages.
Nichrome is a non-magnetic 80/20 alloy comprised of nickel and chromium. This is the most common resistance wire due to its high resistivity and resistance to oxidation at high temperatures. Nichrome is usually wound into coils to allow for high heat applications.
Kanthal alloy, comprised of iron-chromium-aluminium is used in a range of high-temperature applications and brings numerous advantages including flexibility, durability and high tensile strength. It is ideal for use in toasters, home and industrial heaters, kilns and diffusion heaters used for making crystalline silicon. Most recently, Kanthal has been used in the manufacture of electric cigarettes.
Constantan is a copper-nickel alloy with a low-temperature coefficient of resistivity and is easily soldered. It has a high specific heat resistance, is easily ductile, resistant to atmospheric corrosion and has a negligible temperature coefficient making it ideal for commercial applications that require consistent and stable heat or electrical resistance. These include use in Direct Current shunts, specifically to measure temperature in thermocouples, as well as in heavy-duty industrial rheostats and electric motors, and in wire-wound precision resistors.
Balco, a nickel-iron alloy has a very high but more linear temperature coefficient of resistivity making it ideal for use in commercial and industrial sensing equipment. Typical applications include voltage regulators, timing devices, temperature-sensitive resistors, motor controls, precision and vitreous resistors and low temperature heating applications.
What resistance wire does Knight Precision Wire stock?
We stock a large range of resistance wire types including Nichrome 20, 30, 40, 60, 70 and 80, as well as a range of copper alloys, other performance nickel alloys, resistance nickel alloys, conductive copper and stainless-steel wire.