<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>

CC BY-SA 4.0
2020-03-23T03:44:03.207Z
Why “X8” instead of “18”? What do other years/decades use?
KRyan
CC BY-SA 4.0
2020-03-23T05:54:43.237Z
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.
Alex
CC BY-SA 4.0
2020-03-23T13:46:45.223Z
If they're using multiple letter codes/year they presumably refer to different production lines, or production runs.
Dan Is Fiddling By Firelight
CC BY-SA 4.0
2020-03-22T16:36:59.750Z
2020-03-22T16:36:59.750Z
Alex
<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>

<part-identification><piece-information>
What do these numbers on the top of these mini linear actuators denote?
weston
# 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


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## 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.  

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