Gray Metal HOME ABOUT US PRODUCTS CONTACT US Home Gray Metal Products, Inc., a family owned business started in 1906, is a full line manufacturer of heating and air conditioning products. For several decades, Gray Metal Products line has been sold to the wholesale distributors and wholesale hardware chains. Our product lines consist of prefabricated air duct and fittings for HVAC, black stovepipe and fittings, as well as hearth accessories and insulated flexible air duct products.