It must be remembered that a movement might not go straight into a case which itself may have been on the shelf for a while so there will be some overlap, also the hallmarking years of the various assay houses are not in line with each other or the with calendar but the difference is small and the date is likely to be accurate to plus or minus a year.The Waltham Watch Company, also known as the American Waltham Watch Co.Waltham Electric Clock Company began manufacture of various clocks in 1892 under the direction of John Stark, President and Walter Menns, Superintendent.
Many watch companies made hundreds of thousands of watches, and some companies made millions of watches!
It would be impractical to list the individual serial numbers of EVERY watch made... Our serial number tables list RANGES of serial numbers.
In 1850, at Roxbury, Massachusetts, David Davis, Edward Howard, and Aaron Lufkin Dennison formed the company that would later become the Waltham Watch Company.
Their revolutionary business plan was to manufacture the movement parts of watches so precisely that they would become fully interchangeable.
So to determine when your watch was manufactured, you will need to find where your serial number fits within the range of numbers.
Let's say you have a Waltham watch with serial number 21,607,210 as shown in the photo below.
This page contains INSTRUCTIONS for using the serial number look-up tables that are found on many of our watch company history pages.
The example below uses information from the American Waltham Watch Company, but that is just an example.
You should consult the serial number table for the specific brand of watch movement you are trying to date by selecting a company from the menu on the left.