Founded in 1885 and incorporated in 1903, Diamond Iron Works survived until at least 1943. Until at least 1936 they made sawmills and related machinery. It seems that by the mid-1930s they were starting to specialize in mining machinery, especially rock crushers. During their earlier years (1885-1913) they made gas engines, and for a few years (1900-1911) they made the patented "Iron Store Giant" power hammer.

Information Sources

• A 1906 edition of Hendricks' Commercial Register of the United States for Buyers and Sellers lists, under "Hammers (Trip)", "Diamond Iron Works ('Iron Store Giant'), Minneapolis, Minn." The identical listing appears in the 1911 edition. This no doubt refers to the power hammer patented by Hermann G. Dittbenner and assigned to the Minneapolis Iron Store Co. (see Patent 639,538).
• 1908-05-01 The St. Louis Lumberman

  Geo. F. Willis Makes a Change.

  Mr. George F. Willis, who for a number of years past has been connected with leading saw mill machinery concerns in the East and in the West, has become Eastern representative of the Diamond Iron Works, of Minneapolis, Minnesota. Mr. Willis will have his headquarters in Philadelphia, and may be addressed care of Box 144, Philadelphia, Pa.

  Mr. Willis has issued a circular in which he says:
  To Manufacturers of Lumber:
      For many years I have been identified with the Clark Brothers Company, of Belmont, N. Y. in the saw mill machinery trade, but have severed my connection with this concern, beg to announce to my old friends and patrons that I shall in future represent the interests of The Diamond Iron Works, of Minneapolis, Minn. with territory comprising the eastern part of the country, and headquartered at Philadelphia.
      Established in 1885, The Diamond Iron Works have long been rated as belonging to the highest rank of manufacturers of saw mill machinery, and not only build the entire equipment required for mills of any stated capacity, but a great many special machines and labor saving devices used in the cutting of logs and lumber. They have long been famous for their exceedingly heavy gangs, their horizontal resaws and their box-making machinery, while the "Diamond Hog" is known throughout the country as the best of its kind.
      Personally, I am a saw mill designer and engineer, having had twenty years of this experience, not only in the pine and cypress country of the Southern States, but also on the Pacific coast and on Mexican propositions, and during this time I have designed and sold machinery for some of the highest types of modern saw mills in the United States. By virtue of this experience I feel competent to assert that I acknowledge no superior in designing saw mill equipment calculated to secure results and be operated at a minimum of expense.
      Centrally located, with headquarters in Philadelphia, I shall be prepared to confer on short notice with anyone in the market for anything in our line of manufacture, and can furnish expert advice to those interested in saw mills, complete power plants, planing mills and electric light and power plants.
      I shall endeavor to retain the confidence of my old friends and to establish lasting relations with new ones by careful attention to their needs and shall hope to have the opportunity of conferring with you upon anything in our line that you may require.

• The company was assigned patents dated 1920 through 1943. Our list of patents from 1920 onwards is complete, but it is likely that they received earlier patents as well.
• The U. S. Forest Products Laboratory published a booklet dated March 1936, Operating small sawmills, methods, bibliography, and sources of equipment by C. J. Telford. A table lists the makers of various types of equipment, including circular sawmills, band sawmills, edgers, and planers. This company was listed as a maker of circular sawmills and band sawmills.
• American Gasoline Engines Since 1872 by C. H. Wendel, Volume #1, 1983 page 134
• The Complete Guide to Stationary Gas Engines by Mark Meincke, 1996 page 113