This resistance may be used for numerous reasons, including to control the amount of current in a circuit, and also as a heating element. The resistance of wire to conducting an electric current can generate heat, which is utilised in various products such as heaters, toasters, and hairdryers.
Other domestic applications of a resistance wire moreover include remote controls, light bulbs, and phone chargers.
The Resistance Of Wire Explained
Factors That Affect Resistance
There are four main factors which affect the resistance of wire; these should all be considered when calculating the overall resistance of wire. Resistance factors include:
Material – the natural resistivity of a material will affect the overall resistance. For instance, copper is more conductive than steel, so would have a low resistance to an electrical current.
Length – longer lengths of wire have increased resistance to an electrical current compared to shorter wires; this is known as a proportional relationship since resistance increases as length increases. This is because the electrons that carry the electric current through the wire collide with more ions the longer the wire is, making it more difficult for the current to flow.
Thickness – thickness or gauge, also known as the wire’s diameter or cross section, has an inversely proportional relationship to resistance. The thinner a wire is, the greater resistance it has; this is because thinner wire has fewer electrons to carry an electric current.
Temperature – heating a wire also increases the resistance of a wire. A hotter wire will have increased vibration, making it harder for electrons to carry the electric current without interruption from atoms.
Resistance Wire Types
Resistance wire types refers to the combinations of metals within the wire which creates the alloy. The most common type of resistance wire is a nickel and chromium alloy which is used within heating applications. Other common types include constantan (a copper and nickel alloy) which is easily soldered, and a copper, manganese and nickel alloy.
Scott Precision Wire offers several resistance wire types, meeting all industrial needs. Our range of resistance wire includes:
Copper Magnesium: 0.2%; a high strength alloy
Copper and nickel alloys: created for low to medium temperature heating applications, with good corrosion resistance
Cromaloy 1: for good corrosion resistance and high temperature applications
Cromaloy 5: good resistance to oxide scaling and suitable for a range of applications from industrial furnaces to domestic toasters
Cromaloy A: great for high temperature applications with good resistance to Sulphur corrosion
Cumin 11: a copper-based alloy with manganese and nickel, which is suited for DC circuitry
Cupronic 2.5: a copper-based alloy with low resistivity, suitable for low temperature applications
Kutherm 3 & 10: a copper-based resistance wire, with elevated corrosion resistance and temperature resistance properties
Nickel 205: suitable for high temperature applications
Nickel Iron alloys: a self-limiting heating wire for increased temperature control
Stainless steel 304L: a low temperature resistance wire with high strength
For further information regarding Scott Precision Wire’s resistance wire types consult our technical data downloads, or speak to an expert member of our team directly.