THE United States on Tuesday slapped a nearly 16 percent preliminary duty on more than US$100 million worth of steel drill pipes from China.

The action is the latest in a string of cases that the United Steelworkers union and various US steel companies have brought against China.

The 15.72 percent duty applies to the Drill Pipe Master Group, the largest producer in China, as well as all other Chinese producers and exporters.

The US imported US$119.2 million of the pipes from China in 2009, down from US$193.8 million in 2008, the Commerce Department said in a fact sheet on the case.

The case covers drill pipes used in offshore and onshore oil output.

US industry said Chinese drill pipe producers received subsidies in the form of low-cost loans from government-owned banks, export tax incentives, cheap land in "special economic zones" and cheap raw materials from government-owned companies.

The companies and union also want additional duties ranging up to 274 percent to stop sales of the Chinese product in the US at what they said are unfairly low prices.

The department will announce its preliminary decision on those anti-dumping duties in coming months.

The US steel industry has been more active than other sectors in seeking protection against Chinese imports.

In another case last week, the department set final anti-dumping duties ranging up to 143 percent and final countervailing duties ranging up to 437 percent on Chinese steel wire product used in storage rack systems.

It also recently set combined final duties of more than 200 percent on steel gratings used in industrial floors, docks, rampings, staircases and other applications.

Last year, in one of the biggest cases on record, it levied steep anti-dumping and countervailing duties on imports of oil industry steel pipes from China worth US$1.1 billion.