Other metals also gave back some of their intra-day gains - zinc and aluminium had been around fresh cycle highs earlier - but most of the complex finished the year on an upbeat note.
"Copper has been subject to profit-taking, but we've seen good buying in zinc and aluminium. It is not all technical, either, the trade have been on both sides of the market," a trader said.
Zinc stood out, hitting fresh 16-3/4-year highs of $1,925 a tonne as prices broke conclusively above $1,900, before ending at $1,905, still up $22. Year-on-year zinc was up 53 percent.
Copper was pressured down to $4,395, a loss of $47 on the day, having retraced from the $4,512 fresh all-time high hit on Wednesday. However, copper's gains this year have been substantial - up 39.5 percent.
Wider supply concerns continued to cushion the market, which has over-exceeded many expectations as forecasts of a second-half deficit proved unfounded.
On Thursday contract workers at Codelco launched protests to demand a bonus pegged to soaring copper prices, but stopped short of a national strike.
Workers said they would organise national strikes early next week if the state-owned company did not agree to pay them a bonus to reflect prices hitting repeated records.
Aluminium ended at $2,276, down $4, but earlier neared the $2,290 17-year peak hit on Wednesday, having put on 16 percent this year.
Lead was $4 lower at $1,051, but has added five percent this year. Nickel was $150 higher at $13,500, but overall this year has eased nine percent.
Tin was at $6,475, against a previous $6,625. Like nickel, this metal has not been part of the commodity boom and has shed 17 percent this year.