Isn't all copper the same?

For instance, this past Monday I had my regular bucket of #2 that came out of motors, tv's etc. Then, I had found some sort of round, hat shaped copper thingy. I have NO idea what it was, it was dark when I found it so I didnt even realize it was copper until I got it home. I thought it was aluminum. Anyways, when I took it in it weighed up as #3 copper with a 15 cent lower price difference.

I know the difference between number 1 and number 2 copper is mostly the thickness and this thing I found was thin, and it had ''pound'' marks all over it.

At the end of the day though, isn't all copper the same? Or are the different ''numbers'' of copper also different grades?

i thought it was all in the thickness too, i mean apart from insulated, coated etc, copper is copper

The difference between #1 and #2 copper actually has nothing to do with thickness. #1 copper is totally clean, free of any solder, paint or any other contamination. #2 copper is copper with paint, solder or other contamination. #3 copper, as others have said, is sheet copper like downspouts, gutters, roofing, washtubs, and other decorative pieces.

Thickness of copper should only affect your price when selling insulated copper wire because the thicker the copper the higher the recovery rate when the wire is processed.

Originally Posted by KZBell

Clean and shiny angel hair copper will not go as #1 due to the size...it is too small and goes as #2, at my yard anyway.

Not at our yard

I believe most yards prefer it with their #2 because it is not as good for smelting as what typically is bought for #1 copper, similar to the earlier explanation about the lower price for sheet copper.

Originally Posted by SikoraMetals

The difference between #1 and #2 copper actually has nothing to do with thickness. #1 copper is totally clean, free of any solder, paint or any other contamination. #2 copper is copper with paint, solder or other contamination. #3 copper, as others have said, is sheet copper like downspouts, gutters, roofing, washtubs, and other decorative pieces.

Thickness of copper should only affect your price when selling insulated copper wire because the thicker the copper the higher the recovery rate when the wire is processed.

ISRI Spec:
No. 1 COPPER WIRE
Shall consist of No. 1 bare, uncoated, unalloyed copper
wire, not smaller than No. 16 B & S wire gauge.Green copper wire and hydraulically compacted
material to be subject to agreement between buyer
and seller.

Some info here. Copper #3 could fall under the Light copper cat. Scrap Copper Recycling Category -- Non~Ferrous Scrap Metal Recycling

Sheet copper has a lot of surface area which has more exposure to oxygen when smelting than thicker copper. Much of the exposed copper oxidizes (burns) instead of melting. This lowers the recovery rate for thin copper as when compared to the thicker counterparts.