The most actively traded contract, for July delivery, gained 7.50 cents, or 1.8%, to settle at $4.1860 a pound on the Comex division of the New York Mercantile Exchange. This was the highest settlement price in over three weeks and the fourth consecutive day of gains.
Copper futures settled at a three-week high on Friday as a weak dollar and cautious trading boosted prices.
The thinly traded June-delivery contract ended up 7.25 cents, or 1.8%, at $4.1795 a pound. The contract rose 1.5% over the week.
The dollar fell against the euro and hit a record low against the Swiss franc during the day as currency traders avoided the dollar on worries about slowing U.S. growth. The currency moves stoked the appeal of dollar-denominated commodities like copper, which seem cheaper to investors holding foreign currencies when the greenback weakens.