Enamel Wire

If you need enamel wire, but you’re not sure which kind is right for you, then you've come to the right place. Call TEMCo at 877.474.8209 or view our online product selection by clicking the links below.

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Soderon 155 » GP/MR-200 »


What is Enamel Wire?

Enamel wire contains a thin layer of insulation or enamel, made out of either a thin varnish or a polyester or fiberglass yarn. The wire is typically copper or aluminum.


Enamel wire is used to make tight coils of wire in applications such as inductors, transformers, motors, speakers, hard disk head actuators, or electromagnets.

Enamel Wire for Motor Enamel Wire for Speaker Enamel Wire for Transformer

Enamel Wire Specifications

Conductor Type

Most enamel wire will be copper, but some applications will use aluminum wire, such as large transformers and loudspeaker coils.

Aluminum wire requires a cross section that is 1.6 times larger for it to create the same current as a copper wire because aluminum has lower conductivity. This makes aluminum wire more cumbersome than copper wire simply because of how much more wire is required to achieve similar ratings.

Still, aluminum does have the advantage of being less susceptible to corrosion than copper.


Common shapes for enamel wire are square, round or rectangular. Hexagonal wires are also available but they are not as common and can be found in voice coils.

The shape of the wire will determine the tightness of the coil. Since they have less space between the turns when they are formed in a coil, square copper wires will be wound tighter than round wire. Square wires are often used in confined spaces and in applications where higher power is required.

Rectangular copper wire can be wound even tighter than square wire since it is flat. Rectangular wires are arranged in a plane and then laminated into a ribbon.


Enamel wires can come in a variety of colors, including red, green and amber. The color of the wire has no bearing on the properties of the wire. It is purely an aesthetic choice, and no element of how the wire will function, will be impacted.

In cases where a certain wire color is preferred or required by the customers, some manufacturers will provide wire in that specific color. The main reason that one would want wires in different colors is so it is easier differentiate wires coming from different circuits. By making the wires different colors, it makes it clear which conductor is coming from which circuit when soldering.

Color Enamel Wire


If the turns of bare wires, which have no insulation, were to touch, the wire would short out. Insulation allows the wires turns to touch without causing any problems. Insulation is especially important for coils that requires hundreds, possibly thousands, of wire turns.

Different insulation types will have varying thermal capacities and diameters. which can be measured in either millimeters or inches.

Polyester and polyurethane are two popular insulations, but there are a very large number of different types of insulation to chose from, including:

  • Polyester-imide, which has a high thermal endurance and solvent resistance. It comes with increased windability as a result of low friction.
  • Polyamideimide, which is used in applications for inverter duty and motors that may have spikes in voltage.
  • Formvar, which is very flexible and has high abrasion resistance.
  • Polyester Nylon has a dual coat insulation, featuring a polyester basecoat and a nylon topcoat. The polyester gives the wire high thermal properties and the nylon provides the wire with high mechanical properties.
  • Polyester-amide-imide is another dual coat insulation; this one has a polyester basecoat and an amide-imide outer coating. This insulation gives the wire an increased windability, more heat shock resistance and a greater overload capacity. Polyester-amide-imide also provides an increased chemical resistance to many solvents and insulating varnishes.
  • Dacron glass is available as either unvarnished or varnished with organic material or silicon. Dacron glass is served filament that is a combination of glass and polyester fibers. It has good flexibility and is resistant to abrasion.
  • Polyamide-ML is made up of polyimide resins. It is resistant to chemical solvents and burnout. Its high ability to withstand overload and ability to not be affected by exposure to varnish solvents means it is typically used in harsh conditions.
  • Older insulation materials were commonly made out of materials such as cotton, paper, or silk. These are only useful for low-temperature applications, though, as they generally have a thermal rating of 105°C.

    Large power transformers that operate at high voltages may be insulated by oil-impregnated paper or pressboard, which are examples of electrical insulation paper.

    Square or rectangular wires that have thicker than normal insulations can sometimes come with an additional high-temperature polyimide or fiberglass tape, along with an extra varnish to increase the strength and long-term reliability of the winded wire.

    TEMCo offers two types of wire, both with dual insulation: Soderon 155, with a polyurethane insulation and a polyamide overcoat, and GP/MR-200, with a polyester-imide insulation with an overcoat of polyamide-imide.

    Double coated wire strengthens wire and increases durability while allowing the wire to take on the properties of both insulations. The insulation of the GP/MR-200, for example, will allow for an increase in both dielectric properties and chemical resistance to solvents and refrigerants. Soderon 155 will be more resistant to solvents and will have greater windability because of its dual insulation.

    Wire Gauge

    The American wire gauge (AWG) is used in the U.S. and Canada, and it is used represent specific characteristics of round wire, including diameter, resistance and current.

    The gauge will increase as the wire diameter decreases. For instance, wire with a diameter of 6.544 millimeters will have an AWG size of 2, while a wire with a diameter that measures 0.0897 millimeters will have an AWG size of 39.

    There are 44 standard wire gauges in total, the smallest being 0000 and the largest being 40. The 0000 gauge wire will have a diameter of 11.684 mm, while the 40 gauge wire has a diameter of 0.0799 mm.

    Enamel Wire Gauge


    Like the wire diameter, as the wire weight becomes greater, the wire gauge will decrease.

    Wire is measured in weight, instead of length, to ensure its accuracy. Simply put, it is easier to get an accurate weight than to measure miles of wire.

    The 0000 gauge wire will weigh 640.5005 pounds per 1000 feet, while the 40 gauge wire weighs 0.0299 pounds per 1000 feet.

    Temperature Rating/Thermal Class

    The temperature rating, also known as the thermal class, of the enamel wire is the temperature at which the wire will have a 20,000 hour service life. Using the wire at a lower temperature will extend the wire’s service life.

    Thermal class is measured in degrees celsius, with 130°, 155°, 180° and 200° being the common insulation temperatures. The highest temperature rating is 250°.

    Bondable Enamel Wire

    Some wires contain an extra adhesive film, which can be epoxy, polyester or polyamide, on top of the usual insulation. This film will activate when heated up, and the result is known as bondable wire. The turn to turn windings of the wire will bond into a self-supporting coil, removing the necessity for bobbins, which are the spindles that the wire is normally coiled around.

    Solvent, oven and resistance bonding are the three main techniques for creating bondable enamel wire.

    A solvent bonding coat can be put on during the winding process, or can be applied to the completed coil by dipping it in a solvent.

    Oven bonding requires that the wire be fully wound before being heated up in an oven. The size of the coiled wire will determine if the oven bonding time will range from 10 to 30 minutes.

    Resistance bonding is similar to oven bonding, but uses an electric current to heat up the wire instead of an oven. The amount of time it will take to complete the process is dependant on the size of the wire, and the design of the coil. Resistance bonding is used for wires that are 34 gauge or higher.

    Soldering Process

    Soldering is when a wire is fused either to another wire or to a metal circuit board. This done with a third metal, which will be melted down to fuse the wire. The third metal. commonly lead or tin, will have with a lower melting point.

    Depending on the type of wire, it may or may not need to have its insulation removed before being soldered. The GP/MR-200 wire offered by TEMCo, for example, does require that the insulation be removed from the wire first before the wire can be soldered, but the Soderon 155 wire TEMCo offers does not need to have it removed, as the insulation will act as a flux when it is burned.

    Breakdown Voltage

    The insulation dielectric strength is known as the breakdown voltage.

    There are three types of breakdown voltage: Grade 1, Grade 2 and Grade 3. Breakdown voltage grades increase as the insulation becomes thicker. Breakdown voltage is based on AWG standards, with larger gauges having smaller breakdown voltages.

    The insulation thickness is also known as the build, and is the measurement of the enamel. To calculate the build, subtract the total diameter of the wire from the total diameter of the insulation and wire put together.

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

    Where can I purchase Enamel Wire?

    The enamel wire selection from TEMCo is available simply by clicking the links below. The wires available come in numerous different gauges, temperature ratings and insulations. Make sure you are purchasing the right enamel wire by buying from TEMCo today!

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

    Call us at 877.474.8209