The commerce department’s move follows a similar action taken last month on $2.6bn in pipe imports and creates further tension between the US and its biggest trade partner. The US said that China is exporting steel grating, which is used for walkways, platforms and flooring, at rates below market value.

Most Chinese producers of steel grating will now face anti-dumping duties of 145 per cent, which they will have to pay as a cash deposit or bond upon arrival to the US. That rate represents how far below market value the US says China is selling its steel.

According to the commerce department, US imports of Chinese steel grating surged by 538.44 per cent between 2006 and 2008. The US imported $91m worth of steel grating from China last year.

Alabama Metal Industries and Fisher & Ludlow were the US companies that petitioned for the investigation.

China has accused the US of “rampant” protectionism after facing accusations of selling goods such as cars, tyres and chickens below market rates. The Chinese government has reciprocated with its own import duties and has criticised the “Buy American” provisions in the US stimulus package.

Earlier this month China imposed duties on specialty steel products from the US and Russia and last week it said it would slap the European Union with anti-dumping duties for carbon steel fasteners. That was a response to an EU import tax on Chinese shoes.

On Wednesday, the US International Trade Commission will make a final ruling on Chinese subsidies on its exports of steel pipes, which could lead to further anti-dumping duties.