YKK Corporation

YKK is not a company that abandoned zippers and became a window company. In fiscal 2025, Architectural Products generated ¥557.6 billion in sales versus ¥431.4 billion for Fastening, while operating profit ran the other way: ¥39.2 billion for Fastening versus ¥12.0 billion for Architectural Products. The building-products business began in 1959 by extending aluminum mass-production and processing know-how developed for zipper materials. Today YKK operates in about 70 countries and regions, with slightly more employees overseas than in Japan. YKK makes more sense as a company that kept a highly profitable familiar core while growing a second large business from the same manufacturing base.