<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>

CC BY-SA 3.0
2011-11-23T16:57:21.630Z
Good visual explanation.  Amazing little brick.
LarsTech
CC BY-SA 3.0
2011-11-23T17:03:12.677Z
Props to HoMa's World of Bricks for the image.
Zhaph - Ben Duguid
CC BY-SA 3.0
2011-11-23T17:51:23.583Z
I've never seen that brick used that way.
Ambo100
CC BY-SA 3.0
2011-12-01T02:22:28.227Z
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!
retracile
CC BY-SA 3.0
2014-03-12T20:01:34.020Z
@Ambo100 The Cusoo Delorean uses them in [this configuration](http://1drv.ms/1nNAF7t)
Zhaph - Ben Duguid
CC BY-SA 3.0
2015-08-16T09:43:05.573Z
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/)
Todeswaldi
CC BY-SA 3.0
2011-11-23T13:17:37.460Z
2011-11-23T13:17:37.460Z
2017-04-13T12:47:56.213Z
Zhaph - Ben Duguid
<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>

<piece-information><snot>
Why does the Erling brick have a ridge below its outward facing stud?
Ambo100
# 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


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## 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/)  

---

