A limited number of copies of the AMERICAN DIGEST OF BUSINESS MACHINES (1924) is available.  Use the link on the home page to find out how to get your copy.

When Was It Made?

In this section you will be able to identify the date of manufacture by using the serial number from your machine.  If your machine was built after 1924, you will have to send a picture and write me, and I will be able to help you with a rough idea of the date.  You can check below to see if your serial number is within the description and tables. If not, you still have two options. First, you can purchase a copy of the American Digest of Business Machines, published in 1924, and have all of the information at your fingertips.  Use this link to get there: "American Digest",  or you can write me and let me know the serial number of the machine.  Write me at: adders@ix.netcom.com.

Note: The following tables cover the Class 1,2,3 machines only. If you have a Burroughs Portable Adding Machine, follow the link to Dates for Portables.

From The American Digest of Business Machines (1924)

Serial Numbers (approx. 1915 to 1927):

The serial number is stamped on the front of the base of every machine. To provide against the possibility of any confusion in identifying early models from those of modern construction having similar model numbers designations, the serial numbers assigned to each of the early models are listed below in detail.  It will be noted that the serial numbers of all early models are comparatively low -- in all cases less than 260,000 the approximate lowest serial number of machines with class designations.

Until 1914-1915, machines of this make were not numbered in sequence. The practice was to reserve a series of 1,000 to 5,000 numbers (more or less) and assign them to one model, and when that series was exhausted, a new set in a different series would be assigned.  Thus, as will be noticed, a model will have several groups of serials numbers, sometimes in the same year of manufacture.  The intervening numbers were assigned other models.

Dates of Manufacture

When the above plan of numbering was abandoned, a regular sequence was maintained.  Each machine, regardless of its class or model, was assigned a consecutive factory number.  The following table is an approximation of such serial numbers.  The necessity of maintaining sale and consignment stocks of machines of various models often brings about a condition whereby a machine is not sold for many months after manufacture.  Thus, it sometimes develops that, judged by actual date of sale, the following table will not appear correct. The dates shown below are believed to be the approximate dates of manufacture.

Chart for serial numbers 1914 to 1927:

Serial	Date	Serial	Date	Serial	Date
250,000	9/1917	550,000	8/1919	850,000	7/1923
300,000	5/1916	600,000	12/1919	900,000	4/1924
350,000	2/1917	650,000	5/1924	950,000	7/1925
400,000	1/1918	700,000	12/1920	1,000,000	1/1926
450,000	8/1918	750,000	1/1922	1,050,000	7/1926
500,000	3/1919	800,000	11/1922	1,100,000	5/1927

Courtesy of the Charles Babbage Institute, University of Minnesota, Minneapolis

Charts for serial numbers prior to 1914 (refer to model number):

Serials indicate the serial number range.  Carriage type is the width of the carriage in inches. Manufacture year is the approximate year of manufacture (not sale).

A highly detailed serial number listing for machines built before 1910 can be found on the Serials Detail page. It relates the model number to the serial number range.

A cross reference of manufacture dates by serial range can be found on the Models Detail page.

Class 1, Model 1 (first digit of serial number)

Class 1, Model 2 (first digit of serial number)

Class 1, Model 3 (first digit of serial number)

Class 1, Model 4 (first digit of serial number)

Class 1, Model 5 (first digit of serial number)

Class 1, Model 6 (first digit of serial number)

Class 1, Model 6X (first digit of serial number)

Class 1, Model 7 (first digit of serial number)

Class 1, Model 9 (first digit of serial number)

Class 1, Model 11 (first digit of serial number)

Class 1, Model 13 (first digit of serial number)

Class 1, Model 15 (first digit of serial number)

Class 1, Model 17 (first digit of serial number)