Lionel Corporation
Although the smaller, tin lithographed cars by American Flyer, Marx, and others predate the formal O-27 standard, they are also often called O-27, because they also operate flawlessly on O-27 track. Marx may have dedicated its entire line to 0-27, but the Lionel Corporation remains to produce O-27 track and trains. Its tubular rail is a standard of the tinplate era.