- NPK redirects here because that is National Presto's stock symbol. NPK may also refer to the mass percentages of nitrogen (N), phosphorus (P), and potassium (K) present in plant fertilizer.
National Presto Industries is a company founded in 1905 in Eau Claire, Wisconsin[1] and publicly traded on the NYSE and in the "appliances" industry. The company is divided into three so-called "business segments" (divisions). One of those segments manufactures Presto® pressure cookers, which are exported outside the U.S.
