<p>BrickLink calls it a <a href="https://www.bricklink.com/v2/catalog/catalogitem.page?P=737bc01" rel="nofollow noreferrer">train coupler</a>. So it's for trains. (It might also be <a href="https://www.bricklink.com/v2/catalog/catalogitem.page?P=737c01" rel="nofollow noreferrer">a closed variant</a>, I can't tell from the photo.)</p>

CC BY-SA 4.0
2021-08-03T04:21:23.557Z
2021-08-03T04:21:23.557Z
RSchulz
<p>I have 4 of these pieces they are marked Pat Pend. Does any one know what these pieces are? <a href="https://i.sstatic.net/xes1C.jpg" rel="nofollow noreferrer"><img src="https://i.sstatic.net/xes1C.jpg" alt="2x4 plate with round bit" /></a></p>

<part-identification>
What is this part used for? 2x4 plate with a round bit sticking out with a hole
Mikey777
# What is this part used for? 2x4 plate with a round bit sticking out with a hole

(Asked by: username_0 on 2021-08-03)

I have 4 of these pieces they are marked Pat Pend. Does any one know what these pieces are? [![2x4 plate with round bit](https://i.sstatic.net/xes1C.jpg)](https://i.sstatic.net/xes1C.jpg)

**Tags:** part-identification


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## 1 answers

### Answer by username_1 on 2021-08-03. Score: 3

BrickLink calls it a [train coupler](https://www.bricklink.com/v2/catalog/catalogitem.page?P=737bc01). So it's for trains. (It might also be [a closed variant](https://www.bricklink.com/v2/catalog/catalogitem.page?P=737c01), I can't tell from the photo.)


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