WASHINGTON, D.C.: As the deadline for new U.S. steel and aluminum tariffs approaches, manufacturers across the country are already feeling the impact, with prices rising, supply chains tightening, and uncertainty making it difficult for businesses to plan.

For Glen Calder, who runs a small machinery factory in South Carolina, steel costs have jumped more than 15 percent in the past two weeks. Meanwhile, Brian Nelson, who operates a factory in Illinois, says his suppliers have stopped quoting prices altogether.

"They're waiting for the tariffs," said Nelson.

President Donald Trump's plan to impose a 25 percent tariff on imported steel and aluminum will take effect on March 12. While the policy is intended to support domestic production and generate revenue for tax cuts, manufacturers warn that the immediate result will be soaring costs, production delays, and supply chain disruptions.

Steel prices in the U.S. have surged in recent weeks. Hot rolled coil prices in the Midwest jumped 12 percent to $839 per short ton in just two weeks, according to Fastmarkets data. Since Trump took office, prices have climbed 20 percent. In contrast, steel prices in Europe have risen just 6 percent, while those in China have remained largely unchanged.

A Bain & Co. survey found that 40 percent of executives anticipate double-digit increases in input costs due to tariffs, with nearly 80 percent considering revisions to their financial forecasts.

Leon Topalian, CEO of steelmaker Nucor, welcomed the tariffs, calling them a step toward "his America First Trade Agenda." Nucor has already raised steel prices four times since the start of the year.

Manufacturers that rely on steel and aluminum are stuck between rising material costs and resistance from customers unwilling to pay more.

Nelson, CEO of HCC in Mendota, Illinois, says his suppliers have canceled or delayed orders due to tariff uncertainty. "Lead times are getting pushed out because now customers are going crazy, panic buying," he said.

HCC, which produces harvesting reels for farm equipment, must now decide how much of the added cost to absorb. "I said, ‘We'll pass it all on to you—and it's up to you if you want to pass it on to your end customers,'" Nelson said after speaking with a major farm equipment manufacturer.

A survey by S&P Global showed a rise in factory input prices, with purchasing managers blaming tariffs and supplier-driven price hikes.

The White House defended the move, saying the goal is to support domestic producers. "The price of steel and aluminum going up is a natural result of that," a spokesperson said.

The added costs are difficult to absorb for small manufacturers. Calder Brothers, a South Carolina-based paving machine company, is struggling with a 15.2 percent increase in steel costs this month alone.

"This is not a good time to even think about raising my prices," said CEO Glen Calder.

The tariffs extend beyond steel and aluminum. The administration also raised tariffs on Chinese goods by 10 percent, affecting components used by manufacturers like McElroy Manufacturing in Tulsa.

"Absolutely, it will raise prices," said CEO Chip McElroy, who predicted domestic suppliers would price just below the new tariff-inflated costs.

McElroy's company recently surveyed its top 15 suppliers, receiving a range of responses—from "zero impact anticipated" to full certainty that costs will rise as domestic demand increases.