WASHINGTON - The US Commerce Department on Wednesday set preliminary dumping margins on imports of certain iron mechanical transfer drive components from China and Canada, signaling that it may impose punitive duties on those products.

The department made its preliminary affirmative determination that those iron mechanical components, including pulleys, flywheels and bushings, from China and Canada had been sold in the United States at dumping margins of 2.17 percent to 401.68 percent and 100.47 percent to 191.34 percent, respectively.

Punitive duties would be imposed after both the Commerce Department and the US International Trade Commission (USITC) made affirmative final rulings, which are scheduled for October and December, respectively. If the USITC makes a negative determination, the investigations will be terminated.

In 2014, imports of these products from China and Canada were estimated at $274.3 million and $222.3 million, respectively, according to US official data.

The case comes at a time when US steel producers increasingly resort to trade remedy and tariff protection to ride out a sluggish steel market, as steel excess capacity has become an acute global challenge.

US trade experts have warned that resorting to protectionism will not cure the US steel industry's grave ills, and that import restrictions serve to harm the overall US economy rather than help it.

The Chinese Ministry of Commerce has repeatedly urged the United States to abide by its commitment against protectionism and work together with China and other countries to maintain a free, open and just international trade environment.