Answers.Body: <p>The ridge is there to make the base the standard 5LUs wide (see also "<a href="https://bricks.stackexchange.com/questions/39/what-is-an-erling-brick">What is an Erling Brick</a>"), enabling it to accept the standard stud.</p>
  
  <p>I believe the rest of the brick was thinned out so that the combined "depth" of the Erling brick and a 1x1 plate (its common usage as a headlight) was the same height as a standard brick.</p>
  
  <p>From the <a href="http://www.holgermatthes.de/bricks/en/lampenstein.php" rel="noreferrer">HoMa's World of Bricks page on the Headlight Brick</a>:</p>
  
  <blockquote>
    <p>If headlight bricks are turned over by 90° and a plate is attached to the stud then this construction is as high as a standard LEGO brick or a layer of three standard LEGO plates.</p>
  </blockquote>
  
  <p><img src="https://i.sstatic.net/T4pS2.png" alt="Stacked bricks - HoMa&#39;s World of Bricks"></p>
  
  <p>It also helps to keep the 1x1 plate straight to the bricks edge.</p>
  
Answers.ContentLicense: CC BY-SA 3.0
Answers.CreationDate: 2011-11-23T16:57:21.630Z
Answers.Text: Good visual explanation.  Amazing little brick.
Answers.UserDisplayName: LarsTech
Answers.ContentLicense: CC BY-SA 3.0
Answers.CreationDate: 2011-11-23T17:03:12.677Z
Answers.Text: Props to HoMa's World of Bricks for the image.
Answers.UserDisplayName: Zhaph - Ben Duguid
Answers.ContentLicense: CC BY-SA 3.0
Answers.CreationDate: 2011-11-23T17:51:23.583Z
Answers.Text: I've never seen that brick used that way.
Answers.UserDisplayName: Ambo100
Answers.ContentLicense: CC BY-SA 3.0
Answers.CreationDate: 2011-12-01T02:22:28.227Z
Answers.Text: There are a couple more uses as well.  Two Erlings one stud apart can have a horizontal brick connect them.  And you can use 8 to make a cube to which 2x2 plates can be attached (about the size of a Lego die).  Very useful parts!
Answers.UserDisplayName: retracile
Answers.ContentLicense: CC BY-SA 3.0
Answers.CreationDate: 2014-03-12T20:01:34.020Z
Answers.Text: @Ambo100 The Cusoo Delorean uses them in [this configuration](http://1drv.ms/1nNAF7t)
Answers.UserDisplayName: Zhaph - Ben Duguid
Answers.ContentLicense: CC BY-SA 3.0
Answers.CreationDate: 2015-08-16T09:43:05.573Z
Answers.Text: The first use I personally encountered was in 6394: See the top left corner in step 7 of the instructions: [Metro Park & Service Tower](http://peeron.com/scans/6394-1/8/)
Answers.UserDisplayName: Todeswaldi
Answers.ContentLicense: CC BY-SA 3.0
Answers.CreationDate: 2011-11-23T13:17:37.460Z
Answers.LastActivityDate: 2011-11-23T13:17:37.460Z
Answers.LastEditDate: 2017-04-13T12:47:56.213Z
Answers.UserDisplayName: Zhaph - Ben Duguid
Body: <p>Why does the Erling brick (<a href="http://www.bricklink.com/catalogItem.asp?P=4070">#4070</a>) have a ridge below its outward facing stud?</p>
  
  <p><img src="https://i.sstatic.net/DJYy2.gif" alt="enter image description here"></p>
  
  <p>Whereas the more versatile and less common <a href="http://www.bricklink.com/catalogItem.asp?P=87087">#87087</a> does not? The #87087 piece also has a better use in SNOT usage, as it can accomadate larger bricks.</p>
  
  <p><img src="https://i.sstatic.net/qGnwi.jpg" alt="enter image description here"></p>
  
Tags: <piece-information><snot>
Title: Why does the Erling brick have a ridge below its outward facing stud?
UserDisplayName: Ambo100
ThreadText: # Why does the Erling brick have a ridge below its outward facing stud?
  
  (Asked by: username_0 on 2011-11-23)
  
  Why does the Erling brick ([#4070](http://www.bricklink.com/catalogItem.asp?P=4070)) have a ridge below its outward facing stud?
  
  ![enter image description here](https://i.sstatic.net/DJYy2.gif)
  
  Whereas the more versatile and less common [#87087](http://www.bricklink.com/catalogItem.asp?P=87087) does not? The #87087 piece also has a better use in SNOT usage, as it can accomadate larger bricks.
  
  ![enter image description here](https://i.sstatic.net/qGnwi.jpg)
  
  **Tags:** piece-information, snot
  
  
  ---
  
  ## 1 answers
  
  ### Answer by username_1 on 2011-11-23. Score: 22 | Accepted answer
  
  The ridge is there to make the base the standard 5LUs wide (see also "[What is an Erling Brick](https://bricks.stackexchange.com/questions/39/what-is-an-erling-brick)"), enabling it to accept the standard stud.
  
  I believe the rest of the brick was thinned out so that the combined "depth" of the Erling brick and a 1x1 plate (its common usage as a headlight) was the same height as a standard brick.
  
  From the [HoMa's World of Bricks page on the Headlight Brick](http://www.holgermatthes.de/bricks/en/lampenstein.php):
  
  > If headlight bricks are turned over by 90° and a plate is attached to the stud then this construction is as high as a standard LEGO brick or a layer of three standard LEGO plates.
  
  ![Stacked bricks - HoMa's World of Bricks](https://i.sstatic.net/T4pS2.png)
  
  It also helps to keep the 1x1 plate straight to the bricks edge.
  
  > **Comments:**
  > **username_2**: Good visual explanation.  Amazing little brick.  
  > **username_1**: Props to HoMa's World of Bricks for the image.  
  > **username_0**: I've never seen that brick used that way.  
  > **username_3**: There are a couple more uses as well.  Two Erlings one stud apart can have a horizontal brick connect them.  And you can use 8 to make a cube to which 2x2 plates can be attached (about the size of a Lego die).  Very useful parts!  
  > **username_1**: @username_0 The Cusoo Delorean uses them in [this configuration](http://1drv.ms/1nNAF7t)  
  > **username_4**: The first use I personally encountered was in 6394: See the top left corner in step 7 of the instructions: [Metro Park & Service Tower](http://peeron.com/scans/6394-1/8/)  
  
  ---
  
  