Answers.Body: <p>First two digits represent week of production followed by a year.</p>
  
  <p>20X8 - 20th week of 2018.</p>
  
  <p>These codes used for quality control. LEGO Customer Service may ask you to provide this number if there were an issue with a set or particular part.</p>
  
  <p>Similar code exist on box seals too.</p>
  
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2020-03-23T03:44:03.207Z
Answers.Text: Why “X8” instead of “18”? What do other years/decades use?
Answers.UserDisplayName: KRyan
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2020-03-23T05:54:43.237Z
Answers.Text: This is something unknown, probably has some company internal meaning. For example you can find "S" on boxes, "K" on some other parts. I have an old motor base from set of year 2009. It has "J8" for 2008 production year.
Answers.UserDisplayName: Alex
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2020-03-23T13:46:45.223Z
Answers.Text: If they're using multiple letter codes/year they presumably refer to different production lines, or production runs.
Answers.UserDisplayName: Dan Is Fiddling By Firelight
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2020-03-22T16:36:59.750Z
Answers.LastActivityDate: 2020-03-22T16:36:59.750Z
Answers.UserDisplayName: Alex
Body: <p>I'm building 42082 and there are 4 of these but 3 unique numbers in the tops.</p>
  
  <ul>
  <li>20X8 on two</li>
  <li>29X8 on one</li>
  <li>35X8 on another</li>
  </ul>
  
  <p>I'm guessing they are serial numbers from machines that made them but I wondered if someone had a better idea.</p>
  
  <p><a href="https://i.sstatic.net/hZqQq.jpg" rel="nofollow noreferrer"><img src="https://i.sstatic.net/hZqQq.jpg" alt="enter image description here"></a></p>
  
Tags: <part-identification><piece-information>
Title: What do these numbers on the top of these mini linear actuators denote?
UserDisplayName: weston
ThreadText: # What do these numbers on the top of these mini linear actuators denote?
  
  (Asked by: username_0 on 2020-03-22)
  
  I'm building 42082 and there are 4 of these but 3 unique numbers in the tops.
  
  * 20X8 on two
  * 29X8 on one
  * 35X8 on another
  
  I'm guessing they are serial numbers from machines that made them but I wondered if someone had a better idea.
  
  [![enter image description here](https://i.sstatic.net/hZqQq.jpg)](https://i.sstatic.net/hZqQq.jpg)
  
  **Tags:** part-identification, piece-information
  
  
  ---
  
  ## 1 answers
  
  ### Answer by username_1 on 2020-03-22. Score: 10 | Accepted answer
  
  First two digits represent week of production followed by a year.
  
  20X8 - 20th week of 2018.
  
  These codes used for quality control. LEGO Customer Service may ask you to provide this number if there were an issue with a set or particular part.
  
  Similar code exist on box seals too.
  
  > **Comments:**
  > **username_2**: Why “X8” instead of “18”? What do other years/decades use?  
  > **username_1**: This is something unknown, probably has some company internal meaning. For example you can find "S" on boxes, "K" on some other parts. I have an old motor base from set of year 2009. It has "J8" for 2008 production year.  
  > **username_3**: If they're using multiple letter codes/year they presumably refer to different production lines, or production runs.  
  
  ---
  
  