In fact, the standard resistivity of pure copper is 0.0 1709 instead of 0.0 175.
The enameled wire with resistivity of 0.02 is copper-clad aluminum enameled wire. Copper-clad aluminum enamelled wire is made by coating a layer of copper skin on an aluminum core, then coating an insulating paint and drying. There is 28%-40% copper in the copper-clad aluminum enamelled wire market. It is not pure copper enamelled wire, so the resistivity is very high. Generally around 0.026.