What is Magnet Wire?

Learn all about the types and applications of magnet wire and how to select the right kind for you. Call us at 877.474.8209, or view our online product selection below to order your magnet wire.

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What is Magnet Wire?

Magnet wire contains a coat of thin insulation or enamel. Its main use is to transform electrical energy into magnetic energy.

What is Magnet Wire used for?

Magnet wire can be found in applications where tight coils of wire are required. These may include applications such as transformers, inductors, motors, speakers, or hard disk head actuators.

What is Magnet Wire for Motor What is Magnet Wire for Speaker What is Magnet Wire for Transformer

Magnet Wire Specs

Conductor Type

What is magnet wire conductor type? Magnet wire is most frequently made from copper, but there are magnet wires made aluminum as well, usually found on large transformers.

Aluminum wire has a lower conductivity than copper wire. In order for an aluminum wire to create the same resistance as a copper wire, aluminum wire need to have a cross section that is 1.6 times larger. Copper wire is less expensive and more energy efficient than aluminum wire, and that is why it is more commonly used.


What is magnet wire shape and how is it related to its function? Magnet wire can be one of three shapes: square, round or rectangular. The shape of the wire will be a determining factor in how tightly the wire will be coiled.

Round wire will have large spaces between the wires and cannot be wound tightly, while square copper wires will have less space between the turns when they are formed in a coil and can be used in confined spaces. They will also be found in applications that require higher power and that have a larger capacity and wire gauge.

Rectangular copper wires are flat and laminated into a flexible plastic ribbon. Rectangular copper wire is the most easily wound due to its shape.


What is magnet wire color and the relation to its function? The color of magnet wire does not have any bearing on the insulation, diameter or any other element of how the wire will function.

Wires can come in a variety of colors, including red, green and amber.

Manufacturers will sometimes be able provide customers with a specific wire color, in cases where a certain wire color is required.

What is Magnet Wire Color?


What is magnet wire insulation? Magnet wire insulations are either a yarn made out of polyester or fiberglass, a thin varnish, or at times, both.

Square or rectangular wires that have thicker insulations will come with an additional high-temperature polyimide or fiberglass tape in some cases. The windings of these wire are often covered with an extra insulating varnish that is meant to improve the strength and long-term reliability of the wire after it has been winded.

Magnet wire insulation enhances the wire's thermal endurance and protects it from shorting out. Turns of wires that are bare, meaning they have no insulation, are not able to touch each other, while insulated wire can be wound so that the wire winds do touch. In the case of a wire needing to have hundreds or thousands of turns, the wire will require protection from insulation.

Different insulation types will have different specifications, including thermal capacity, diameter, weight, AWG wire size and application.

Some common types of insulation include polyester and polyurethane.

TEMCo offers wire with a polyurethane insulation overcoated with polyamide, which will have a thermal rating of 155°C and Polyester-imide insulation overcoated with polyamide-imide, which has a thermal rating of 200°C.

Older insulation materials were made of substances like cotton, paper, or silk, but these types of insulation are only useful for low-temperature applications that have a thermal rating of 105°C.

Wire Gauge

What is magnet wire gauge? American wire gauge (AWG) is used in the U.S. and Canada to represent specific characteristics of round wire, such as diameter, resistance and current.

Diameter and AWG number numbers are inversed: as the wire diameter decreases, the AWG number increases. For example, a wire with an AWG size of 3 will have a diameter that measures 5.827 millimeters, while a wire with an AWG size of 38 will have a diameter of 0.101 millimeters.

Wire gauges range from 0000-40, meaning there are 44 in total. The smallest gauge wire will have a diameter of 11.684 mm, while the largest gauge wire has a diameter of 0.0799 mm.

Any wire size beyond those gauges would be too small to be measured in millimeter, and would need to be measured in ohms instead.

What is Magnet Wire Gauge?


Similarly to wire diameter, wire weight is inversely related to AWG number. As the gauge becomes greater, the weight of the wire will decrease.

The largest wire weight is 640.5005 lbs per 1000 feet, with a gauge of 0000, while the smallest weight is 0.0299 lbs per 1000 feet for a 40 gauge wire.

Temperature Rating/Thermal Class

What is magnet wire temperature rating in relation to how it functions? The thermal class, or temperature rating, is the temperature at which the wire will have a 20,000 hour service life. If used at a lower temperature, the service life of the wire will be extended.

Thermal class is typically measured in degrees celsius.

Some common insulation temperatures you will find are 130°, 155°, 180° and 200°. The maximum thermal class that will be found is 250°.

Bondable Magnet Wire

Bondable wire will have an adhesive film on top of the usual insulation. This film will activate when heated up and will bond the turn to turn windings of the wire into a self-supporting coil. This eliminates the need for the spindles around which the wire is wound, also called bobbins.

Bonding agents include epoxy, polyester and polyamide.

The three main bonding techniques are: solvent, oven and resistance.

Solvent will be applied either while the wire is winding, or the coiled wire will be dipped in the solvent once the wire has been fully wound.

Oven bonding requires that the wire is fully wound and then heated up in an oven. This allows the wire to bond. Depending on the size of the coiled wire, oven bonding can range from 10 to 30 minutes.

Resistance bonding is the same process as oven bonding, but with an electric current to heat up the completed coil instead of an oven. The amount of voltage and time necessary to complete the process are dependent on the size of the wire and the design of the coil. Resistance bonding is generally for wires that are 34 gauge or higher.

Soldering Process

Soldering is when two metals are consolidated together by a third metal. The third metal will be melted and will fuse the other two together when it solidifies.

What is magnet wiring soldering process? Most magnet wire currently does not require that its enamel be taken off before the wire is soldered, as the insulation will act as a flux when it is burned. Older wire, however, might require the insulation to be removed first before the wire can be soldered, though.

Breakdown Voltage

What is magnet wire breakdown voltage? Breakdown voltage in an indicator of the dielectric strength of the wire's enamel insulation.

The breakdown voltage can be one of 3 types: Grade 1, Grade 2 and Grade 3. The thicker the insulation, the higher the breakdown voltage and the higher the grade.

The insulation thickness, or build, is the thickness of the enamel that has been added to the circumference of the insulated wire. The insulation thickness can be determined by subtracting the diameter of the bare wire from the diameter of the insulated wire.

Insulation can be single, heavy, triple or quadruple build. Single and heavy are the most common.

Breakdown voltage is based on AWG standards, with smaller gauges having higher breakdown voltages.

Where can I purchase my Magnet Wire?

TEMCo offers wires in different gauges, temperature ratings and insulations. Please view the magnetic wire selection from TEMCo by clicking the links below to order online, or call us at 877.474.8209.

View Soderon 155 Wire Selection View GP/MR-200 Wire Selection

Call us at 877.474.8209