I sawed off the plating to see if they were copper plated. This product does not use copper. The author is wrong! I'm not sure what kind of metal alloy it is that can't be soldered if you want a solid connection and not a crimp. The thickness of the caliber is also smaller, no copper, a strange alloy, not solderable, less material in composition (thinner caliber). Cannot be used when dealing with resistance or corrosion issues. USE ONLY FOR BASIC CONNECTIONS IN A DOOR PROJECT. THE PRICE IS GOOD EXCEPT INCORRECT INFORMATION PROVIDED BY THE SELLER