Reportedly beginning in 1876, Wm. H. Warren manufactured metalworking machinery, notably planers, shapers and radial drilling machines; The radial drills became his specialty.

By 1891 the business name was William H. Warren Machine Tool Works, and we have also seen other names such as the Warren Machine Co., the Warren Machine Tool Co., and the Warren Tool Works, but none of those name seem to be official and correct names.

In October 1899 it was announced that the Wm. H. Warren Machine Tool Works had been sold to Rudolph Kirschbaum of Berlin, Germany. In December of that year, William H. Warren died. In May of 1901 it was announced that the Wm. H. Warren Machine Tool Works' operations had been moved the new plant of Rudolph Kirschbaum in Berlin. Kirschbaum's acquisition included all patent rights for Warren's radial drilling machines.

Information Sources

• 1873 Worcester Directory (Drew, Allis & Co.) lists "Warren Wm. Henry, machinist, Hammond, n. R. R. house 53 Oxford / Warren Wm. Henry (C. & W. H. Warren), bds. 28 Washington".
• 1883 Worcester Directory (Drew, Allis & Co.) lists three different William H. Warren: "Warren William Henry, stairbuilder, h. 28 Washington"; "Warren William H. express agent, house 9 Glen"; "Warren William H. machinist, 10 Harris ct."
• 1891-08-13 The Iron Age page 260. "The W. H. Warren Machine Tool Works at Worcester, Mass., have received a $25,000 contract for building machinery for the Watervliet Arsenal at West Troy, N. Y."
• 1891-11-12 The Iron Age page 844. "Business with the L. W. Pond Machine Company of Worcester, Mass.,... They are at present engaged in building one of their standard 48x48 inch by 16 foot planers with four heads for the Cooke Locomotive and Machine Company of Paterson, N. J., also one of the same pattern for the W. H. Warren Machine Tool Works of the same city..."
• 1893-06-08 The Iron Age page 1304, in a list of members of the Massachusetts Hardware Dealers' Association, lists "William H. Warren, M. C. Warren & Co., Boston."
• 1895-10-31 The Iron Age page 885, article on the "Warren Traverse Head Shaper" built by the William H. Warren Tool Works of Worcester, Mass. This is the only mention of this firm that can be found in a search of Google Books, other than other journals reprinting this article or mentioning the article.
• 1896-07-04 The Electrical World, page 27, article on the "Universal Radial Drill" from the Wm. H. Warren Machine Tool Works, Worcester, which "has been prominent in the manufacture of drilling machines since 1876. The machine illustrated weighs 10,500 pounds. "The company also manufactures a drill of smaller size and three of larger size."
• 1899 Industrial Chronology. "October... Warren Machine Co. sold to Rudolph Kirschbaum, Berlin, Germany... December. Deaths during month: Wm. H. Warren, of Warren Machine Co., aged 61 years..."
• February 1901 Machinery (Vol. 7, No. 6), page 169, has a writeup on the W. H. Warren Machine Tool Works, Worcester, and how they cut the wormwheel on the end of the radial arm of their radial drilling machines.
• 1901-05-23 The Iron Age page 27, in a column on the businesses of Worcester. "All the business of the Warren Machine Company has been moved from Worcester to Berlin, Germany, to be part of the new plant of Rudolph Kirschbaum in that city. The company built the Warren universal drill. Mr. Kirschbaum acquires the patent rights on the device for the United States and foreign countries."
• September 1901 Shop Talk (a promotional publication of machinery retailer Hill, Clarke & Co.), full-page ad for Warren Universal Radial Drills. The illustrated machine reads, "The Wm. H. Warren Machine Tool Works. Worcester, Mass." The November 1901 issue carried a similar ad that said "A special lot of first-class machines on our hads must be closed out at a price."
• 1919 book, History of Worcester and Its People, Volume 4, page 506, in a biography of James Anthony Colvin. "For several years he manufactured machine tools as the proprietor of the Warren Machine Tool Company, but about 1896 he sold his interests in this concern to German manufacturers..."