Enter the serial number of your Steinway & Sons piano to find the year it was made and its year of manufacture. It is usually 6 digits long unless you have a very old Steinway piano.
Steinway pianos are either manufactured in New York, USA or Hamburg, Germany. There is no clear way to determine this from the serial number alone. However, most pianos found in North and South America were manufactured in New York, and most located in Europe and the rest of the world were made in Hamburg.
The serial number is found on grand pianos on the plate in between the bass and treble tuning pins under the music desk. On uprights it is at the top right hand side if you open the top lid.