KB Duct is the nation’s largest manufacturer of industrial Duct work & Custom fabrication. With over a century in business, KB Duct offers a comprehensive selection of industrial ducting made in the USA. KB Duct offers flanged and clamp­-together ducting parts and accessories, as well as an unparalleled capacity for customized duct components and special fabrications. From a basic drawing, KB Duct can manufacture unique individual duct parts or design a full 3­D ductwork system, all while maintaining the demonstrated level of quality that experts across the country have come to rely on.