AOS

A. O. Smith Corporation

A maker of water heaters and water-treatment systems, A. O. Smith is one of the largest suppliers of residential and commercial water heaters in North America, sold under its own name and brands to homeowners, plumbers, and builders. It began in 1874 in Milwaukee as a small metalworking shop making parts for baby carriages and bicycles, and later built the first pressed-steel automobile frames for early automakers like Ford. The company is named after Arthur Oliver Smith, the founder's son, and it famously entered water heating through a 1930s process for fusing glass to steel—a trick first used on brewery beer kegs.