Don’t know the age of your piece?
Check to see whether it bears a US patent number. It won’t tell you the date of manufacture, but by checking the Patent Office website (see below) you can determine the earliest date it may have been made. For example, a kitchen utensil with patent number 2153321 could not have been manufactured prior to 1939. It is also possible to view actual patents by conducting a search on the same website.
United States Patent and Trademark Office
http://www.uspto.gov/web/offices/ac/ido/oeip/taf/issuyear.htm “Table of Issue Years and Patent Numbers, for Selected Document Types Issued Since 1836”
Don’t forget to bookmark this site. You’ll want to be able to find it again.