The Metropolitan Railway H Class consisted of eight 4-4-4T steam locomotives, numbered 103 to 110. They were built by Kerr, Stuart & Co of Stoke on Trent in 1920 at a cost of £11,575 each. These locomotives were purchased for the express passenger trains on the Metropolitan Railway's mainline between Harrow (later Rickmansworth)—the change point from electric locomotives—and Aylesbury or Verney Junction.