Reading Date Codes On Panasonic Relays

November 22, 2011
By Anonymous

Reading Date Codes

Date codes, or lot numbers, are used in manufacturing to identify when a component was made. It can be used for production quality control, as well as tracing purposes in the factory. Panasonic uses three different code formats to identify the date on a Relay:

  1. Three digit code: The first digits represent the year, and the remaining two digits represent the week number in a calendar year.  Example: 645 means week 45 of  year 2006.
  2. Four digit code: The first two digits represent the year, and the remaining two digits represent the week number in a calendar year.  Example: 0451 means week 51 of year 2004.
  3. Five digit code: The first digit represents the year. The second and third digits represent the month, and the remaining two digits represent the day.  Example: 41201 means December 1st, 2004.

Sometimes a letter will follow the date code. The letter represents the factory in which the relay was manufactured. Examples:

For relays manufactured after June of 2005, the date code nomenclature will not have the "NAiS" logo.  Instead, "M" will be used as shown in the TK1-5V relay above.