Great Lakes steel production plunged to 646,000 tons last week, down 6.2 percent from the previous week.
Steel mills in the Great Lakes region made 689,000 tons of metal the previous week, according to the American Iron and Steel Institute. Most of the steel made in the Great Lakes region is produced around the southern shore of Lake Michigan in Lake and Porter counties in Northwest Indiana.
Overall, domestic steel mills made 1.851 million tons of metal last week, down from the 1.856 million tons made the previous week.
U.S. steel mills have run at a capacity utilization rate of 77.5 percent so far this year, up from 74.4 percent at the same point in 2017, according to the AISI.
Domestic steelmakers used about 79 percent of their steelmaking capacity in the week that ended Oct. 6, up from 73.2 percent at the same time a year ago but down from 79.2 percent a week prior, according to the American Iron and Steel Institute.
Some analysts say steel-making capacity utilization of about 90 percent is considered financially healthy for the industry, at least for the larger integrated mills like those around Lake Michigan in Northwest Indiana, because of their high fixed operating costs.
Nationally, as 25 percent Section 232 tariffs make imports more expensive, steel output is up by 4.6 percent so far this year, according to the American Iron and Steel Institute, a 0.1 percent increase as compared to the past week and the sixth straight week of increase.
Production in the Southern district, a wide geographic swath that includes many mini mills, rose to 720,000 tons last week, up from 670,000 tons the previous week.
Steel output in the greater Midwest rose to 196,000 tons last week, up from 187,000 tons the previous week.