<p>I had two of these bricks in red, one is broken (one of the side-caps dropped off): there's just a piece of galvanized iron/steel in it.</p>

<p>My blocks were bought about 19 years ago, so maybe they changed the weight to an other/cheaper material in the meantime, but I don't think so.</p>

CC BY-SA 3.0
2011-10-26T18:43:17.620Z
This seems like it's correct. I'm going to do what Zhaph said and test it with a magnet.
Pubby
CC BY-SA 3.0
2011-10-26T20:34:55.323Z
i'm not 100% sure it's iron/steel, but it pretty much looks like because it's galvanized, wich won't make much sense on other metals. i'm looking forward to the results of your magnet-test.
oezi
CC BY-SA 3.0
2011-10-26T05:47:35.807Z
2016-01-11T21:40:58.807Z
2016-01-11T21:40:58.807Z
oezi
<p>I'm fairly sure it's one or two pieces of iron, but I would need to check with someone who actually opened one. You can easily check that it's a <em>ferrous</em> metal if it attracts magnets.</p>

CC BY-SA 3.0
2011-10-26T15:17:23.717Z
Non-ferrous metals aren't magnetic... so a lack of attraction doesn't rule out the possibility of a metal being used ;)
Zhaph - Ben Duguid
CC BY-SA 3.0
2011-10-27T07:32:51.330Z
Indeed, I oversimplified it, I guess I'll edit that in. But magnetic attraction will confirm it's a ferrous metal, and since I was pretty sure it's iron (as [confirmed](http://bricks.stackexchange.com/q/159) by oezi), I didn't want to bother thinking about other metals.
Joubarc
CC BY-SA 3.0
2017-12-14T07:13:23.180Z
Lego magnets stick to them just fine.  It takes two magnets to lift one brick.
Mark
CC BY-SA 3.0
2011-10-26T05:01:48.283Z
2011-10-27T06:55:47.927Z
2011-10-27T06:55:47.927Z
Joubarc
<p>I did the unthinkable!  ...I had to know.</p>
<p>I opened one of my two weighted bricks.  One of the two ends has a glued-on cap that I've cut around using a utility knife.</p>
<p><img src="https://i.sstatic.net/LHuig.jpg" alt="enter image description here" /></p>
<p>The piece of metal it contains fits almost perfectly in the cavity.  I don't know metals but it has a rainbowish kind of sheen to it.  Here's a close-up:</p>
<p><img src="https://i.sstatic.net/3rePG.jpg" alt="enter image description here" /></p>
<p>I'm now reassembling it back and super glueing it.</p>

CC BY-SA 3.0
2011-11-22T16:35:47.773Z
+1, for defacing a LEGO brick to provide an answer. I imagine you could weigh it to find it's mass.
Ambo100
CC BY-SA 3.0
2011-12-06T10:43:55.553Z
Since when is defacing a LEGO brick worth +1? Heretic!
Joubarc
CC BY-SA 3.0
2012-02-08T17:59:01.927Z
Makes sense that these would be galvanized steel since they were often used to balance the floating boats (e.g. 314, 4005, 4010, 4025, etc.) and could be reasonably expected to get wet and rust leaking out of the brick would look weird.
Robert C. Barth
CC BY-SA 3.0
2012-03-01T15:40:25.880Z
I literally gasped when I saw this.
Matthew Crumley
CC BY-SA 3.0
2015-09-11T18:31:48.287Z
I don't know whether to upvote this answer for being correct, or downvote for cutting lego bricks apart. This sort of experiment would never get past the ethics panel in my household.
Mr. Shiny and New 安宇
CC BY-SA 3.0
2018-01-08T11:12:09.230Z
I have one that had been opening itself by the side for like... forever. And I didn't use any violent mean for it to reveal its shiny insides. Note that the side can be clipped back. I thus always thought that this was meant to be possible to open/close this container.
Lulhum
CC BY-SA 4.0
2019-05-12T14:04:29.100Z
I did this back in the mid 90s because I too had to know. Now that we all know, I wonder if you could replace it with something even heavier. Are there any safe denser metals that aren't too expensive? A lead alloy maybe? Just under 2 ounces isn't all that much weight.
l008com
CC BY-SA 4.0
2019-10-30T15:00:41.977Z
@l008com Go for tungsten. Almost twice as heavy as lead without the health hazards
pcantin
CC BY-SA 4.0
2011-11-02T00:34:03.083Z
2024-05-18T14:51:12.767Z
2024-05-18T14:51:12.767Z
pcantin
<p>I own a few bricks that contain a weight inside of them. 52g according to Lego.</p>

<p><img src="https://i.sstatic.net/1LN5L.jpg" alt=""></p>

<p>What exactly is inside of <a href="http://www.bricklink.com/catalogItem.asp?P=73090b" rel="noreferrer">these bricks</a> that makes them heavy?</p>

CC BY-SA 3.0
2011-10-26T06:59:21.860Z
Are you talking about these [lego train weight parts](http://en.bricker.ru/parts/73090a/) ?
Riduidel
<piece-information><disassembly><weight>
What is inside the "weight element" brick?
Pubby
# What is inside the "weight element" brick?

(Asked by: username_0 on 2011-10-25)

I own a few bricks that contain a weight inside of them. 52g according to Lego.

![](https://i.sstatic.net/1LN5L.jpg)

What exactly is inside of [these bricks](http://www.bricklink.com/catalogItem.asp?P=73090b) that makes them heavy?

**Tags:** piece-information, disassembly, weight

> **Comments:**
> **username_1**: Are you talking about these [lego train weight parts](http://en.bricker.ru/parts/73090a/) ?  

---

## 3 answers

### Answer by username_6 on 2011-11-02. Score: 40 | Accepted answer

I did the unthinkable! ...I had to know.

I opened one of my two weighted bricks. One of the two ends has a glued-on cap that I've cut around using a utility knife.

![enter image description here](https://i.sstatic.net/LHuig.jpg)

The piece of metal it contains fits almost perfectly in the cavity. I don't know metals but it has a rainbowish kind of sheen to it. Here's a close-up:

![enter image description here](https://i.sstatic.net/3rePG.jpg)

I'm now reassembling it back and super glueing it.

> **Comments:**
> **username_7**: +1, for defacing a LEGO brick to provide an answer. I imagine you could weigh it to find it's mass.  
> **username_3**: Since when is defacing a LEGO brick worth +1? Heretic!  
> **username_8**: Makes sense that these would be galvanized steel since they were often used to balance the floating boats (e.g. 314, 4005, 4010, 4025, etc.) and could be reasonably expected to get wet and rust leaking out of the brick would look weird.  
> **username_9**: I literally gasped when I saw this.  
> **username_10**: I don't know whether to upvote this answer for being correct, or downvote for cutting lego bricks apart. This sort of experiment would never get past the ethics panel in my household.  
> **username_11**: I have one that had been opening itself by the side for like... forever. And I didn't use any violent mean for it to reveal its shiny insides. Note that the side can be clipped back. I thus always thought that this was meant to be possible to open/close this container.  
> **username_12**: I did this back in the mid 90s because I too had to know. Now that we all know, I wonder if you could replace it with something even heavier. Are there any safe denser metals that aren't too expensive? A lead alloy maybe? Just under 2 ounces isn't all that much weight.  
> **username_6**: @username_12 Go for tungsten. Almost twice as heavy as lead without the health hazards  

---

### Answer by username_2 on 2011-10-26. Score: 13

I had two of these bricks in red, one is broken (one of the side-caps dropped off): there's just a piece of galvanized iron/steel in it.

My blocks were bought about 19 years ago, so maybe they changed the weight to an other/cheaper material in the meantime, but I don't think so.

> **Comments:**
> **username_0**: This seems like it's correct. I'm going to do what Zhaph said and test it with a magnet.  
> **username_2**: i'm not 100% sure it's iron/steel, but it pretty much looks like because it's galvanized, wich won't make much sense on other metals. i'm looking forward to the results of your magnet-test.  

---

### Answer by username_3 on 2011-10-26. Score: 6

I'm fairly sure it's one or two pieces of iron, but I would need to check with someone who actually opened one. You can easily check that it's a *ferrous* metal if it attracts magnets.

> **Comments:**
> **username_4**: Non-ferrous metals aren't magnetic... so a lack of attraction doesn't rule out the possibility of a metal being used ;)  
> **username_3**: Indeed, I oversimplified it, I guess I'll edit that in. But magnetic attraction will confirm it's a ferrous metal, and since I was pretty sure it's iron (as [confirmed](http://bricks.stackexchange.com/q/159) by username_2), I didn't want to bother thinking about other metals.  
> **username_5**: Lego magnets stick to them just fine.  It takes two magnets to lift one brick.  

---

