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Enameled Copper Wire vs Enameled Aluminum Wire

Updated : Feb. 19, 2024

Enameled wire is a major type of winding wire, consisting of a conductor and insulation layer. After annealing to soften the bare wire, it undergoes multiple layers of coating and baking to form.

Enameled copper wire and enameled aluminum wire are both common types of enameled wire. So, what are the differences between them?

copper vs aluminum wire

Comparison table of copper and aluminum conductor performance

Performance Aluminum Copper
Tensile strength N/mm² 120 260
Resistivity (20℃)Q.mm²/m ≤0.028264 ≤0.017241
Temperature resistance aR/℃1 0.00429 0.00393
Thermal expansion coefficient μm/m.℃ 23.8 16.6
Thermal conductivity coefficient W/m.K 226 402
Melting point℃(Pure metal) 660.4 1083
Boiling point℃(Pure metal) 2467 2567
Density g/mm3(Pure metal) 2.703 8.92

Metal substrate

Enameled aluminum wire is made of pure aluminum or aluminum alloy as the substrate, coated with insulation paint on the surface to make the wire material, while enameled copper wire is made of pure copper or copper alloy as the substrate covered with insulation paint film.

Metal substrate


Due to aluminum's density being only 1/3 of copper's, enameled aluminum wire is significantly lighter than enameled copper wire for the same cross-sectional area. Enameled aluminum wire has a great advantage in weight-sensitive applications, such as small household appliances, mobile phones, and aerospace electronic equipment.


Since copper has a lower resistivity than aluminum, enameled copper wire has better conductivity than enameled aluminum wire. Therefore, in applications where resistivity is critical (such as high-sensitivity components and high-frequency transmission), enameled copper wire is the preferred choice.

Tensile strength

Copper wire is characterized by high hardness, high strength, and good ductility, with a tensile strength of up to 260 N/mm², while aluminum wire has a tensile strength of only 120 N/mm². The elongation at break of copper ranges from 15-35%, while for aluminum, it is 10-30%. Therefore, enameled copper wire is less prone to fracture and has an advantage in high-strength applications.

Tensile strength


Copper is a more expensive metal, so enameled copper wire is typically more costly. Aluminum is cheaper than copper, making enameled aluminum wire generally more competitively priced. In some conventional applications, using enameled aluminum wire can lower costs.

Welding method

Due to the differences in melting point and thermal conductivity between aluminum and copper, enameled aluminum wire typically requires specialized aluminum solder and welding techniques for joining, while enameled copper wire can be welded using conventional methods such as arc welding, gas shielded welding, spot welding, etc.

Stripping method

When chemically stripping enamel, aluminum is more sensitive to oxidation and requires specialized chemical solvents. Copper, with its relatively stable chemical properties, can be dissolved using more common organic solvents such as acetone or ethyl acetate.


Both enameled aluminum and copper wires are used in various electronics, appliances, tools, motors, relays, and transformers. Enameled copper wire is pricier and suited for high-end products and critical components like high-end appliances and motors. In contrast, enameled aluminum wire is more cost-effective and suited for lower-end products and conventional electronics.