U.S. manufacturing has shifted from a nearly 11% share of the economy a decade ago to just 8% this year. But these numbers are not granular enough to provide much meaning. Many manufacturing industries continue to expand or are, indeed, just getting started, while some others still are experiencing major declines. Here are three of the expanding subsectors, according to a new report by IBISWorld, a market-research firm: Chemical manufacturing accounts for about 16% of total manufacturing value-added to the U.S. economy, and it is burgeoning. The main growth engine is output of refined petrochemicals resulting from the American boom in hydraulic oil and gas fracturing. Another main growth engine is organic chemical making, which provides raw materials for manufacturers in China and other low-cost countries. Also, rising production of vitamins, supplements and generic pharmaceuticals has boosted this sector. Machinery manufacturing. Capital equipment has been another bright spot, including heavy equipment for agriculture, oil and gas production and construction. Exports have been a big boon to this sector, such as the bulldozers and other big pieces sent abroad by Caterpillar. The revival of domestic construction activity after the Great Recession also has boosted activity and employment in machinery manufacturing. “Chemical manufacturing accounts for about 16% of total manufacturing value-added to the U.S. economy, and it is burgeoning.” Fabricated metal product manufacturing. Companies forging, stamping, forming and machining metal products have seen growth as the U.S. economy picks up steam and as they have increased exports, whose share of revenue in the subsector has climbed to an expected 11% this year from under 7% in 2005. Valve manufacturing oil and gas exploration and petrochemical production has been the fastest-gaining subsector in this category. On the flip side, here are three manufacturing sectors IBISWorld says are in the midst of contraction: […]