In the early 1890s, Stehman, Jenks & Stehman made watch-makers lathes. By 1898 the partnership had become Stehman & Stehman. By 1913 the business had become the Stehman & Swan Manufacturing Co. We cannot find evidence of the business surviving past the end of World War I.

All of these firms kept exceptionally low profiles and there is little evidence of their existence other than some patent assignments and some surviving lathes as documented on lathes.co.uk. All the additional data points that we have are listed below.

Information Sources

• Seen on eBay: "Vintage bench ball vise... Marked Stehman & Stehman makers Lancaster, Pa. Made in U.S.A. Patent date August 31st 1886. Overall it is about 3 3/4 inches tall x 3 inches diameter..."
• 1898-10-26 : "Lancaster, Pa., Oct. 19.—At 2.30 o'clock Monday morning the large frame machine shop of Stehman & Stehman, which was in the rear of E. S. Stehman's residence, corner of Pine and Chestnut Sts., was completely destroyed by fire. At the above hour a Mrs. Boyle saw flames bursting from the shop, which is opposite her home. She aroused some neighbors, and an alarm was quickly turned in. The building was entirely frame and in 20 minutes it was a heap of smoking ruins. The burned shop was about 100 feet long and 40 feet deep. It was partly one story and the rest two stories in height."
• 1899 Annual Report of the Factory Inspector of the Commonwealth lists "Stehman & Stehman, N. Mulberry st., [makers of] Engraving blocks, etc."
• 1899-12-09 The Engineering Record: "Stehman & Stehman, Lancaster, Pa., are erecting a new factory for the manufacture of engraving blanks, etc., which will have a 30-H.-P. engine and 40-H.-P. boiler."
• September 1913 The Metal Industry: "The Stehman & Swan Manufacturing Company have bought the property at 856 North Prince street and are making the old line of Stehman tools. They will also make some new lines and enlarge."
• 1914-10-17 Electrical Review has a lengthy article on lock making and details the production facilities of a Lancaster, Pa. lock manufacturer. Their machinery included "one Stehman & Swan speed lathe" and "one Stehman & Swan cylinder riving machine."
• 1917-18 Fogerty's Directory of the Jewelry and Kindred Trades lists "Stehman & Swan Mfg. Co. (Inc.) 520 Harrisburg Ave. [Lancaster, Pa.] under "Jewelry Manufacturers" and "Tools and Supplies".
• From the 1996 book, Pennsylvania Clockmakers and Watchmakers, by James B. Whisker. "Stehman, Henry. clockmaker. 1829-32, Lancaster boro [tax; Wood and Kramer, p. 29]. 1835-49, Middletown, Dauphin County [tax]. / Stehman & Stehman. manufacturers of lathes and watchmaker's tools. 1896, Lancaster boro [Dun's Pa. Mercantile Reference Book]."
• A 2008 Lee Valley Tools newsletter has an article on a Stehman, Jenks & Stehman engraver's vise.