Copper or aluminum in refrigeration compressor?

I just found a sure way to determine if a compressor has copper or aluminum windings. Knock off the electrical box and drill a tiny pilot hole in the center between the prongs. Follow it with a 1/2 inch hole, then drill into the windings. Peek in with a flashlight to see if they are aluminum or copper.

Awesome. Gonna do this. Have a bunch sitting around.