Answers.Body: <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>
  
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2021-08-03T04:21:23.557Z
Answers.LastActivityDate: 2021-08-03T04:21:23.557Z
Answers.UserDisplayName: RSchulz
Body: <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>
  
Tags: <part-identification>
Title: What is this part used for? 2x4 plate with a round bit sticking out with a hole
UserDisplayName: Mikey777
ThreadText: # 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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