Our Projects

Sheet Metal Connectors, Inc. was proud to fabricate the ductwork for the new Medical Biosciences Building at the University of Minnesota.

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SMC supplied rectangular ductwork as well as E-Z Flange spiral pipe and fittings to outfit the new University of Minnesota-Duluth AMSOIL Arena with a first class duct system.

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Making Spiral Duct

Sheet Metal Connectors Inc. – Spiral duct is manufactured from a variety of metals, including galvanized, stainless steel, aluminum, polyvinyl coated and paint grip. Spiral duct machines wind a continuous sheet of strip metal, about six inches wide, locking the edges together and forming it into a continuous spiral tube. The four-ply spiral lockseam serves as a continuous reinforcing rib, boosting the pipe’s crushing resistance to more than twice that of longitudinal lockseam or welded pipe. The stronger, more rigid construction also allows long lengths of spiral duct to be made in a wide range of diameters, from three to 96 inches and manufactured in lengths from one to 20 feet.


Common methods of sealing spiral ductwork include standard slip-fit connections which require the application of caulk or some other joint sealant. In addition, top ductwork manufacturers now offer factory-applied gaskets that effectively seal spiral duct connections without the use of sealants.

Latest News

Watch our video slideshow from the Minneapolis, Minnesota facility. Photos of the Minneapolis, Minnesota Sheet Metal Connectors (SMC) Facility. We are a leader in commercial HVAC Systems. SMC is a...
Sheet Metal Connectors, Inc. is proud to support the Cystic Fibrosis Foundation’s Breath of Life Gala.   The annual Breath of Life Gala is the top fundraiser for the Minnesota Chapter of the...
How shape and a new connection technology contribute to high-performance HVAC systems.   Besides improving the energy efficiency of HVAC systems, round ductwork cuts installed costs and adds...