20th century in the United States. At the end of the 19th century the mechanical power hammer became popular in smaller blacksmith and repair shops. These machines were typically rated between 25 and 500 pounds of falling weight. Many may still be seen in use in small manufacturing and artist-blacksmith shops today. In the middle of the 20th century power hammers driven by compressed air began to gain popularity and several manufacturers are currently producing these hammers today. References Further reading Freund, Douglas, Pounding Out The Profits, Mingus Mountain Machine Works, Jerome AZ, 1997 External links Power hammer at the East Broad Top Railroad Hammers Metalworking tools Articles containing video clips