For identification research, the critical date is the 'Introduction Date', the date the watch model was first introduced to the public for sale. If you are attempting to identify your watch, that is, you are seeking the model name and other detailed information about it, then you are actually looking for a different date. Let's call this date, the date your Wadsworth case was made, the Wadsworth Date. If you want to know the exact age of your watch, then this date is what you are seeking. The Wadsworth case date is the date the watch's case was manufactured. While these tables appear simple, like all Gruen research work, considerable effort was expended by these individuals to create them.īefore presenting the tables and techniques, a word about case dating. These techniques involve looking up a portion of the Wadsworth case serial number in a table to determine the date a Gruen case was manufactured. Both are top-notch Gruen historians and researchers. One was developed by Jack Wood, the other Barry Cooper. There are two different case dating methods for Gruen wristwatch cases that were manufactured by Wadsworth. Another wrench (spanner for you Brits) in the toolbox is always welcomed as Gruen collectors need all the help they can get. I'm grateful that I can share with you MORE tools for your Gruen toolbelt. Woodĭating A Gruen Wristwatch from a Wadsworth Case Serial Number Movement will render a date earlier than your watch’s ageīe aware your watch may not contain its original movement and thus theĬopyright 2012, 2013 M. Movements could have been made years prior to its incorporation into ‡ Coincident with the highest 405/406 caliberĪ few caveats when dating your watch, specifically *Some low-numbers after the reset continue to have “ pre-reset ” markings You need not concern yourself with these notes.ĭetails of that data derivation then dig in! This table is the same as the previously published one in 2012, but has been refined to be more accurate.įor 405 406 410 411 420 421 425 426 calibers and their sweep versions Movement needs to have these two characteristics:ġ. The latest refinement includes extending the table This table is for the 405, 420 and 425 basedĬalibers and is a guide for determining the approximate date of Movements in the 405 410 420 & 425 families has been cracked. Gruen Movement Dating using Movement Serial Number

Kahr serial number manufacture date