July 30 (Reuters) - The United States will impose a 50%

tariff on copper pipes and wiring, President Donald Trump said

on Wednesday, but details of the levy fell short of the sweeping

restrictions expected and left out copper input materials such

as ores, concentrates and cathodes.

U.S. Comex copper futures plunged 19.5% after the

announcement, quickly unwinding a premium over the London global

benchmark that had grown in recent weeks as traders had assumed

U.S. copper mines would see a financial benefit from the tariff.

Trump first teased the tariff in early July, implying

that it would apply to all types of the red metal, ranging from

cathodes produced by mines and smelters to wiring and other

finished products.

Yet in a proclamation released by the White House, the

administration said the tariff will apply only to semi-finished

copper products and other products that copper is heavily used

to manufacture, starting on Friday.

"Copper is being imported into the United States in such

quantities and under such circumstances as to threaten to impair

the national security of the United States," Trump said in his

proclamation.

The tariffs will exclude copper scrap and copper

concentrates, mattes, cathodes and anodes, some of the main

products of copper mines and smelters.

The move is essentially a boost to Chile and Peru, two

of the world's largest copper miners.

"The newly announced copper tariffs are far from

universal tariffs that markets were concerned about," said

Gracelin Baskaran, director of the critical minerals security

program at the Center for Strategic and International Studies.

"It's less punitive than markets initially expected."

The measure came after a U.S. investigation under Section

232, which Trump ordered in February. The report was delivered

to the White House on June 30 by Commerce Secretary Howard

Lutnick, according to the proclamation.

Trump said he may still impose further tariffs, and has

asked Lutnick to provide an update on the domestic copper market

by June 2026. At that point, Trump will evaluate whether to

impose a phased universal import duty on refined copper of 15%

starting in 2027, and of 30% starting in 2028, he said.

Along with tariffs, the order calls for steps to support the

domestic copper industry, including requiring 25% of

high-quality scrap produced in the U.S. to also be sold within

the country.

Freeport-McMoRan ( FCX ), the largest U.S. copper producer,

said it would comment after it reviewed Trump's order in detail.

Chile's Codelco, the world's biggest copper producer,

praised the exclusion of cathodes as a positive for the company

and for Chile, which is the top supplier of refined copper to

the U.S.

BHP, which operates the world's largest copper

mine in Chile, and Antofagasta ( ANFGF ), which ships copper from

Chile to the U.S. and wants to build a U.S. copper mine, did not

immediately reply to requests for comment.