Domestic steelmakers in the U.S. slashed prices in February to cope with a flood of imports juiced by the strong dollar, a move that will pressure their profit margins and reduce costs for buyers of steel, including auto makers.

Imports rose 33% in January compared with the year before, according to figures released Wednesday by the American Iron and Steel Institute, reaching 3.85 million tons, compared with 2.9 million tons a year earlier. The jump in imports comes as oil and gas drillers cancel orders for steel pipe, underscoring the resilience of overall U.S. demand compared with other markets.

Now, the muscular currency is making foreign steel less expensive by comparison, and “is fighting against us in a very big way,” said Lisa Goldenberg, president of Delaware Steel Co., a Fort Washington, Pa.-based steel trading company.

The imports are rising off an already high 2014 base. Imports of steel from Russia jumped 96% in 2014 from a year earlier, to 6.5 million tons, while imports from China rose 69% to 2.8 million tons.

To stem that tide, steelmakers with major U.S. operations such as ArcelorMittal, U.S. Steel Corp. and Nucor Corp. have cut prices in the past few weeks, according to steel distributors who buy from them. The benchmark hot-rolled coil index is down 17% since the start of the year, to around $500 a ton, its lowest level since August 2009.

Stuart Barnett, president of Highland Park, Ill.-based steel distributor Barsteel Corp., said imports are now between 15% and 20% of his product mix, from a usual level of about 5%. Barsteel annually ships around 85,000 tons of steel to manufacturers, auto makers and mining companies. Mr. Barnett said he would like to buy more steel from U.S. suppliers, and that he still relies on the domestic industry for “higher-tech steels, like for seat belt clips and bumpers, in the U.S.”

Mr. Barnett sees a direct correlation between exchange rates and oil prices, and the surge in imports. “If you produce oil and you export steel, your currency will go down and your steel will be less expensive,” he said referring to Brazil, Mexico and Russia.

The price cuts should curb imports somewhat.

“Suddenly you can buy domestic American hot-rolled coil for the same price you can buy it from India, Egypt or Turkey,” said Barry Bernsten, managing partner at American Steel Industries LLC, a steel importer and distributor. Overall, foreign steel has been consistently available at a discount, he said.

Steel industry leaders have talked openly of their desire for anti-dumping tariffs to further deter imports, but haven’t yet filed a trade case. To win such a case, they would have to prove that foreign steelmakers are selling in the U.S. below cost, and that this is hurting American steelmakers. They are working on mounting a case, according to a person familiar with the matter, although putting together such a dossier takes time.

The market share for foreign-made finished steel was an estimated 32% in January, its highest level ever, said Kevin Dempsey, senior vice president of policy and general counsel for trade association American Iron and Steel Institute. Import levels are “extreme,” he said.

“One thing is crystal clear, that we have been injured” by imports, AK Steel Chief Executive James Wainscott told analysts last month. “How fast we can prove injury and how quickly we can accelerate the process is key.”

The situation is reminiscent of the 1990s, steel company officials said. At that time, a surge of imports and a robust dollar helped pave the way for a wave of bankruptcies for American steelmakers, despite a strong economy.

Nucor and U.S. Steel didn’t return calls seeking comment.

The lower steel prices are good news for makers of cars and car parts, construction companies and other major buyers of steel. Ford Motor Co. said it was “starting to see good news” on commodities when it reported earnings last month.

Steel industry insiders don’t expect prices to recover until May at the earliest. “You’ve got the flood in imports, a fall in iron ore and scrap prices, and the domestic steel service centers are over-inventoried,” said John Packard, publisher of Steel Market Update, an industry newsletter. “Prices will recover in May if we see imports shrinking and we see domestic service centers reducing their inventories.”