Since 1966, Cincinnati-based Langdon, Inc. has fabricated sheet-metal ductwork and related components from its 50,000-square-foot facility. The company stands out for its patented duct connections and products such as Sure•Clamp™ Access, a removable duct section designed to simplify fire-damper inspection and maintenance. Its engineering and estimating teams also develop custom applications for commercial and industrial projects.
NFPA 80 (2013) Compliance
Compliance program
SMACNA Standards
Compliance program
Metro Duct Systems, IncFor more than five decades, Metro Duct Systems, Inc. has designed and fabricated custom ductwork for commercial and residential clients across the tri-state area and New Jersey. Based in Long Island City, the company also handles ductwork installation and as-built drawings, bringing its sheet-metal expertise to projects that require tailored fabrication.ASTORIA, NY
Hennemuth Metal FabricatorsHennemuth Metal Fabricators is a family-owned and operated ductwork manufacturer and distributor founded in 1954 by Gordon Hennemuth. Based in Oakdale, Pennsylvania, the company fabricates custom duct and fittings for commercial and residential HVAC contractors, with in-house spiral and rectangular duct production. Its 60,000-square-foot fabrication shop opened in 2018, and the business reports more than 100 years of combined staff experience.OAKDALE, PA
Duro Dyne CorporationFounded in 1952, Duro Dyne Corporation manufactures sheet metal accessories and equipment for the heating, ventilating, and air-conditioning industry. Headquartered in Long Island, New York, it also has manufacturing and warehousing facilities in Ohio, Colorado, and Canada. Its long-standing product innovations include flexible duct connectors and hand-held pinspotter machines.BAY SHORE, NY
Southwark Metal Manufacturing CoFounded in 1946, Southwark Metal Manufacturing is a third-generation family-owned company that makes sheet-metal ductwork for residential and light-commercial HVAC systems. It operates seven U.S. facilities and describes itself as one of the largest manufacturers in this specialty, with more than 3,000 stock items and custom fittings produced for wholesale distributors.PHILADELPHIA, PA