Here we have a "Quarter Donut" made of copper. When a voltage is applied, the current travels from positive to ground. When asked about the current density, 1.1021 x 10^7 A.
For a spring made out of aluminum, the current density read 88438 A.
For a gold coil, the current density read 7242.5 A.
Finally, for a much larger spring made of copper, the current density comes out to 28619 A.