Raw steel production in the Great Lakes region surged to 621,000 tons last week, up from 593,000 tons a week earlier.

Local steel output has been much lower than normal all this year amid a torrent of imports that now account for a historic 32 percent of the total market share. Overall U.S. production trails 2014 by 7.3 percent.

Great Lakes steel production rose by 28,000 tons, or 4.7 percent, in the week that ended Saturday, according to an American Iron and Steel Institute estimate. Overall U.S. steel output rose by 1.4 percent over the same period.

Most of the raw steel production in the Great Lakes region takes place in the Chicago area, mainly Lake and Porter counties in Northwest Indiana. Indiana has led the nation in steel production for more than 30 years

Production in the Southern District, which encompasses mini-mills across the American South, dipped to 599,000 tons last week, down from 602,000 tons the week before.

Total domestic raw steel production last week was about 1.747 million tons, up from 1.722 million tons a week earlier.

Nationally, domestic steel mills had a capacity utilization rate of 73.9 percent last week, up from 72.8 percent a week earlier. The capacity utilization rate had been 78.5 percent at the same time a year earlier.

Year-to-date output has been 40.1 million net tons, at a capacity utilization rate of 72.4 percent, according to the American Iron and Steel Institute.