The color of the copper is brown, as if it were scrap, not pure, original copper
공급업체의 응답:
Dear, we do not sell scrap copper. If you see the surface turning black, it is because we are cold drawn copper wire. Since you only requested a sample, we did not perform polishing treatment. This is just a natural oxidation reaction of copper. Regarding purity, you can freely test it, which is 99% pure copper.
16 Apr 2024