(Adds duties for specific countries, steelmakers) The U.S....

(Adds duties for specific countries, steelmakers)

The U.S. Commerce Department on Friday set final anti-dumping duties on hot-rolled flat steel from Japan, South Korea, Turkey, Britain, Brazil, the Netherlands and Australia on Friday, locking in import taxes of 3.7 percent to about 34.3 percent for five years.

The ruling, which could still be overturned by the U.S. International Trade Commission, is the latest in a series of U.S. actions aimed at fighting a glut of steel imports as China's economy slows and demand remains weak elsewhere.

The department also imposed final anti-subsidy duties of 3.9 to 11.3 percent against most steelmakers in Brazil, Turkey and South Korea, but slapped 57 percent anti-subsidy duties on top Korean steelmaker POSCO 005490.KS and Daewoo International Corp.

The final duty rates follow preliminary determinations in January and March.

The highest anti-dumping taxes of 34.3 percent were imposed against Brazil's Usiminas USIM5.SA , with all other Brazilian producers facing 33.1 percent margins and just over 11 percent anti-subsidy duties.

The Brazlian government has threatened to challenge the U.S. duties before the World Trade Organization.

Britain's Tata Steel UK TISC.NS saw its U.S. anti-dumping margin reduced from nearly 50 percent in the preliminary finding to about 33 percent, while Tata Steel's Netherlands operations faces final dumping duties of 3.73 percent.

Used in automotive applications, construction, tubing and heavy machinery, hot-rolled steel imports from the seven countries more than doubled to nearly $2 billion last year, with the largest share, about $650 million, coming from South Korea.

The International Trade Commission is due to decide by late September whether the imports from these countries were unfairly traded and had caused injury to domestic producers.

At a hearing on the issue on Thursday before the commission, American steel executives argued that Chinese mills were overproducing steel of all types, causing a global supply glut that has prompted steelmakers elsewhere sell hot-rolled product below cost into the United States, the only market with significant demand. This caused prices to plunge and several U.S. steel mills to be idled last year.

"Globally, demand for steel is very anemic. There is every incentive in the world for foreign producers to ship product --dump product -- into the United States," said Richard Blume, general manager of U.S. steelmaker Nucor Corp NUE.N "Basically, they are exporting their unemployment to the U.S."

South Korean steel producers argued in briefs in the case that imports were not to blame for the hot-rolled price drop in the United States.

Instead, they said the lower prices were due to falling demand for oil drilling pipe, lower raw material costs, and shipping bottlenecks that caused West Coast industries to turn to Asian suppliers.