Answers.Body: <p>The <a href="https://www.bricklink.com/v2/catalog/catalogitem.page?P=71155#T=C" rel="noreferrer">web pieces made of flexible string</a> are perfectly serviceable real-life webs, even if they are too small for most applications.</p>
  <p>Of course the LEGO brand <a href="https://rebrickable.com/parts/73092/magnet-cylindrical/" rel="noreferrer">magnets</a> are working real-life magnets as well.</p>
  <p>Some sets have included large <a href="https://brickset.com/parts/design-76543" rel="noreferrer">air bellows</a> that could be compressed manually (i.e. hit) to supply a burst of air to launch a projectile or a <a href="https://brickset.com/parts/design-87945" rel="noreferrer">racecar</a>.</p>
  <p>The <a href="https://brickset.com/parts/design-98785" rel="noreferrer">light-up bricks</a> are naturally serviceable as tiny flashlights.</p>
  <p>The <a href="https://brickset.com/sets/8878-1/Rechargeable-Battery-Box" rel="noreferrer">rechargeable</a> <a href="https://brickset.com/parts/design-19106" rel="noreferrer">batteries</a> are usable outside of the LEGO world as batteries.</p>
  <p>The <a href="https://brickset.com/parts/design-61403" rel="noreferrer">large sawblade</a> used in some constructible action figure lines (for example <a href="https://brickset.com/sets/71312-1/Ekimu-the-Mask-Maker" rel="noreferrer">Bionicle</a>) and System lines (for example <a href="https://brickset.com/sets/8963-1/Rock-Wrecker" rel="noreferrer">Power Miners</a>) with the right setup could be used as a table saw to cut through paper or other materials of comparable strength.</p>
  <p>The <a href="https://brickset.com/parts/design-43364" rel="noreferrer">parachutes</a> of the 2019 City Police sets are advertiesed as working parachutes, so I'd expect them to be ... working parachutes, at least for loads comparable to minifigures.</p>
  <p>Almost all LEGO <a href="https://brickset.com/parts/design-6041" rel="noreferrer">propeller</a> pieces are functional propellers (having pitch and accepting an axle), with admittedly terrible performance compared to purpose-engineered examples.</p>
  <p>The <a href="https://brickset.com/sets/5311-1/Two-2-x-2-Plates-with-Wire-25-6-cm" rel="noreferrer">old-style 9V</a> and newer <a href="https://brickset.com/parts/design-21655" rel="noreferrer">PF electric extension wires</a> could be used as real wires.</p>
  <p>The <a href="https://brickset.com/parts/design-61929" rel="noreferrer">electrical switches</a> (or polarity changers) are working too.</p>
  <p>In the same vein, the pneumatic components (<a href="https://brickset.com/parts/design-74982" rel="noreferrer">pump</a>, <a href="https://brickset.com/parts/design-88355" rel="noreferrer">tube</a>, <a href="https://brickset.com/parts/design-19474" rel="noreferrer">valve</a>, <a href="https://brickset.com/parts/design-19475" rel="noreferrer">cylinder</a>, <a href="https://brickset.com/parts/design-75974" rel="noreferrer">tank</a>, <a href="http://www.brickfactory.info/scans/0009000/9641/030.jpg" rel="noreferrer">manometer</a>) are working as well.</p>
  <p>The Technic <a href="https://brickset.com/parts/design-76537" rel="noreferrer">shock absorbers</a> (springs) would apply too, some are even <a href="https://brickset.com/parts/design-47373" rel="noreferrer">adjustable</a>.</p>
  <p>Naturally, all Technic <a href="https://brickset.com/parts/category-Technic/tag-Gear?query=gear" rel="noreferrer">gears</a> are working gears, even if they have suboptimal shapes and materials compared to real-world examples.</p>
  <p>The LEGO City <a href="https://brickset.com/parts/design-10035" rel="noreferrer">mugs</a> can actually hold tiny amounts of liquids.</p>
  <p>The <a href="https://brickset.com/parts/design-2551" rel="noreferrer">boat</a> <a href="https://brickset.com/parts/design-28925" rel="noreferrer">hull</a> <a href="https://brickset.com/parts/design-62792" rel="noreferrer">pieces</a> that are advertised as being able to float, do of course float.</p>
  <p>The treasure chest, large barrel and letterbox pieces are tiny, but functional storage items.</p>
  <p>Some City sets include working car jacks.</p>
  <p>LEGO has produced mirror pieces with stickers that really reflect light and of course all transparent window panels let light through. On the same topic, many door elements have working hinges and the tiny fences could be used to separate tiny gardens and to keep tiny animals from crossing over. (Caveat: almost all animals that are small enough that can't just step over it can probably climb over or fit through the holes)</p>
  <p>Possibly the most boring example of all: the <a href="https://brickset.com/parts/design-73843" rel="noreferrer">weighted brick</a> does indeed weight quite a lot due to a metal insert and is thus usable as counterweight.</p>
  
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2019-04-16T13:21:21.167Z
Answers.Text: Not sure the boat hull pieces really count - I mean, LEGOs are made of plastic, and thus _all_ float (possible exception of the weighted brick).  Being boat hull-shaped does not necessarily make any difference in that respect...
Answers.UserDisplayName: Darrel Hoffman
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2019-04-16T13:42:50.580Z
Answers.Text: @DarrelHoffman Certainly not all bricks float and lots of them do so only as long as the air bubbles trapped on the underside are not dissolved in the water. See for example: https://bricks.stackexchange.com/a/9013/3631
Answers.UserDisplayName: zovits
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2019-04-15T15:05:09.223Z
Answers.LastActivityDate: 2020-06-18T16:54:30.270Z
Answers.LastEditDate: 2020-06-18T16:54:30.270Z
Answers.UserDisplayName: zovits
Answers.Body: <h2>All Aboard!</h2>
  
  <p>I'd like to add my all-time favorite LEGO piece:</p>
  
  <ul>
  <li>x870cc02, <strong>THE BLACK WHISTLE!</strong></li>
  </ul>
  
  <p><a href="https://i.sstatic.net/uIlbe.jpg" rel="noreferrer"><img src="https://i.sstatic.net/uIlbe.jpg" alt="enter image description here"></a></p>
  
  <p>The white brick is a microphone. Attach it to your train's motor and <strong>BLOW THAT WHISTLE</strong>!  Depending on how short (or LONG!) your whistling was, the train would go forwards or backwards. </p>
  
  <ul>
  <li>Real-world use: Not only did it drive your train round the bend, <strong>but your parents too...!</strong></li>
  </ul>
  
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2019-04-16T20:45:37.160Z
Answers.Text: You got two awesome items in one post!. The microphone is awesome too!
Answers.UserDisplayName: djsmiley2kStaysInside
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2019-04-14T00:13:52.500Z
Answers.LastActivityDate: 2019-04-14T00:13:52.500Z
Answers.UserDisplayName: Uli
Answers.Body: <p>One obvious answer is all components of the power functions family.  <a href="https://i.sstatic.net/tRBSY.jpg" rel="noreferrer"><img src="https://i.sstatic.net/tRBSY.jpg" alt="all components of the power functions family"></a> </p>
  
  <p>Lights can be used as lights, motors can be used as motors.</p>
  
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2019-04-13T17:44:26.707Z
Answers.LastActivityDate: 2019-04-13T20:34:47.947Z
Answers.LastEditDate: 2019-04-13T20:34:47.947Z
Answers.UserDisplayName: Metalbeard
Answers.Body: <p>Gears function quite well for creating mechanical devices such as functioning clocks:</p>
  <p><a href="https://i.sstatic.net/jEmJA.jpg" rel="nofollow noreferrer"><img src="https://i.sstatic.net/jEmJA.jpg" alt="KEvronista skeleton clock" /></a>
  <a href="https://www.youtube.com/watch?v=O-h6MMkNL_w" rel="nofollow noreferrer">Design by KEvronista</a>, picture by me.</p>
  <p>Naturally you can use an electric motor for more accurate timekeeping, as in the NXT Classic Clock (bonus model from Lego):</p>
  <p><a href="https://i.sstatic.net/x2LBi.png" rel="nofollow noreferrer"><img src="https://i.sstatic.net/x2LBi.png" alt="Screenshot of NXT Classic CLock" /></a></p>
  <hr />
  <p>LEGO Mindstorms robotics kits are also a great way for kids and adults to get started with robotics, and I would bet that a good number of current robotics and mechanical engineers got their start with building LEGO robots. There's a healthy educational community and competitions such as FIRST Robotics.</p>
  
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2019-04-15T22:01:01.210Z
Answers.LastActivityDate: 2020-08-02T21:07:39.040Z
Answers.LastEditDate: 2020-08-02T21:07:39.040Z
Answers.UserDisplayName: qwr
Answers.Body: <p>Those shoehorn pieces worked. Technically, all of them serve their intended purpose as bricks. The ropes function. The ball shooting contraption present in the Lego Ninjago dragons (and other sets, I bet) functioned, as well as the spring-loaded cannon pieces. The axles technically worked (but not very well in actual cars).</p>
  
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2019-04-14T16:53:27.453Z
Answers.Text: I've seen them serve [their 'intended' purpose](https://seenaroundboston.com/wp-content/uploads/2016/05/lego-patch-hole-in-brick-wall-642x482.jpg) in the real world. My favorite piece though: **the winch**.
Answers.UserDisplayName: Mazura
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2019-04-15T13:44:47.110Z
Answers.Text: What do you mean by "Those shoehorn pieces"?
Answers.UserDisplayName: zovits
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2019-04-15T15:16:46.503Z
Answers.Text: The brick puller?
Answers.UserDisplayName: Jarod Thornton
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2020-05-28T20:09:23.693Z
Answers.Text: @Mazura My antivirus says that webpage is dangerous.
Answers.UserDisplayName: mindstormsboi
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2020-05-28T20:52:32.100Z
Answers.Text: @mindstormsboi - mine too. It's a picture where someone used a bunch to tuck point some missing (actual) bricks on the corner of a house.
Answers.UserDisplayName: Mazura
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2019-04-14T05:17:45.757Z
Answers.LastActivityDate: 2019-04-14T05:17:45.757Z
Answers.UserDisplayName: Bricky McBrickface
Answers.Body: <p>Minifig accessory "shovel" can be used for dispensing minute amounts of a powder. Urban legend attributes such usage to drug dealers.</p>
  
  <p>The fact that <a href="https://rads.stackoverflow.com/amzn/click/com/B00K2BP8Q8" rel="noreferrer" rel="nofollow noreferrer">amazon lists</a> digital pocket scale (0,1 g resolution, 100g max) and an airtight container as "frequently bought together" hints it's more than just a legend and LEGO shovels are indeed used in this way.</p>
  
  <p><a href="https://i.sstatic.net/cf7tj.png" rel="noreferrer"><img src="https://i.sstatic.net/cf7tj.png" alt="printscreen"></a></p>
  
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2019-04-16T20:23:08.397Z
Answers.Text: This is the best answer. Welcome to Bricks.SE.
Answers.UserDisplayName: Metalbeard
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2019-04-16T20:32:49.630Z
Answers.Text: Look at the insane price for the shovel! Bricklink lists it as [Minifigure, Utensil Shovel (Round Stem End)](https://www.bricklink.com/v2/catalog/catalogitem.page?P=3837&name=Minifigure,%20Utensil%20Shovel%20(Round%20Stem%20End)&category=%5BMinifigure,%20Utensil%5D#T=S&O={%22iconly%22:0}), not to be confused with the much more expensive [Minifigure, Utensil Shovel (Flat Stem End)](https://www.bricklink.com/v2/catalog/catalogitem.page?P=88431&name=Minifigure,%20Utensil%20Shovel%20(Flat%20Stem%20End)&category=%5BMinifigure,%20Utensil%5D#T=S&O={%22iconly%22:0}).
Answers.UserDisplayName: Metalbeard
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2019-04-16T20:35:34.137Z
Answers.Text: @Aziraphale When you're weighting a powder that's worth $100 per gram, $4.69 is reasonable investment : )
Answers.UserDisplayName: Agent_L
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2019-04-17T09:02:32.313Z
Answers.Text: If anyone are interested, I can probably find some of those shovels to sell for $4.00 (that's a discount on several times the average price on bricklink for those).
Answers.UserDisplayName: Henrik supports the community
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2020-05-28T20:07:41.813Z
Answers.Text: Now the link says "page not found"
Answers.UserDisplayName: mindstormsboi
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2020-05-29T14:42:26.923Z
Answers.Text: @mindstormsboi Thanks, that's why I put the screenshot.
Answers.UserDisplayName: Agent_L
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2019-04-16T17:35:07.030Z
Answers.LastActivityDate: 2019-04-16T17:35:07.030Z
Answers.UserDisplayName: Agent_L
Answers.Body: <p>The holes in Lego Technic work very well as holes. </p>
  
  <p>By which I mean, I have built very successful motor-driven cross slides for small machine tools using Technic pieces.</p>
  
  <p>When paired with nominally 4.8mm metric ground rod (which tends to have a negative tolerance) the 4.8mm holes are a nice sliding fit. Imperial 3/16" rod at about 4.76mm also works, but is a bit sloppier.</p>
  
  <p>Although the hole is a little undersized for tapping M6 (5.0 required), the soft plastic easily allows a taper tap to be run through. The 1mm pitch of the thread, together with the hard metric 8mm width of the brick means that the start and finish phase of the threads is identical. If an already tapped brick is pegged as a guide to a new brick, then (a) the guide will help ensure that thread goes in straight and (b) has the same phase in both bricks. I mark a guide brick, so there's no cummulative error in creating new tapped bricks.</p>
  
  <p>A piece of 6mm studding can then be used as a lead screw. It can be fitted concentrically to Technic shafts by locknutting it to a tapped brick, then pegging the brick to a 40t gear.</p>
  
  <p>That's all been taken apart now. But only last week I had a measurement problem, and needed to be able to adjust the height of a stage quickly between many, repeatable, fairly precise heights. Behold, two sets of binary stacking gauge blocks, 16x8mm down to 1x8mm.</p>
  
  <p><a href="https://i.sstatic.net/v35DV.jpg" rel="nofollow noreferrer"><img src="https://i.sstatic.net/v35DV.jpg" alt="enter image description here"></a></p>
  
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2019-04-16T05:52:17.567Z
Answers.Text: "Technic", not "Technik". (I don't know if there's anything else to fix in your answer, or I'd edit the fix in myself.)
Answers.UserDisplayName: V2Blast
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2019-04-14T06:08:45.517Z
Answers.LastActivityDate: 2019-04-28T19:53:01.087Z
Answers.LastEditDate: 2019-04-28T19:53:01.087Z
Answers.UserDisplayName: Neil_UK
Answers.Body: <p>I once published a paper in a peer reviewed scientific journal using data gathered using a remote translation stage constructed from Lego Technic. </p>
  
  <p>I could only get ~ +-1mm accuracy out of it, where the proper stages were more like +- 0.1mm, but it was good enough for a proof of concept and the proper stages were on back order.</p>
  
  <p>Of course many people would say that an X-Ray Physics lab is not the real world, but that's another matter!</p>
  
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2019-04-16T05:59:19.693Z
Answers.Text: citation needed ;-)
Answers.UserDisplayName: uhoh
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2019-04-16T08:19:24.850Z
Answers.Text: lol, this is the paper https://scripts.iucr.org/cgi-bin/paper?aj5138, but oddly enough I didn't mention what the translation stage was made from in the text!
Answers.UserDisplayName: Joseph Rogers
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2019-04-16T08:32:03.850Z
Answers.Text: non-paywalled paper, where I can almost see the stage moving along the axis in Figure 1.  https://ore.exeter.ac.uk/repository/bitstream/handle/10871/22169/X-ray%20diffraction%20from%20bone%20employing.pdf?sequence=1 Speaking of X-rays and tracks, you may also like [Where (if anywhere) were X-ray machines put on trains or trolleys to image “Everybody over 14 years old”?](https://history.stackexchange.com/q/50628/33008)
Answers.UserDisplayName: uhoh
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2019-04-16T08:37:26.933Z
Answers.Text: nice find, that's actually a different paper from the same research group but it's the same geometry being exploited, that one's from after I left the group so they'll have been using proper equipment by then (so was I after the very first PoC experiments)
Answers.UserDisplayName: Joseph Rogers
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2020-07-23T12:44:48.693Z
Answers.Text: Another scientific experiment that uses Lego is the [squeezed light](https://en.wikipedia.org/wiki/Squeezed_states_of_light) source of the gravitational-wave detector GEO600, which uses black Lego bricks for stray light baffles in its optical assembly. Here's an old [video documentary](https://youtu.be/nYaDW43aHa0?t=78) 
   (in German) where two of the scientists test the best colour to use and you can see the finished result on p. 82 of this [thesis](https://doi.org/10.15488/7661) (if you look closely).
Answers.UserDisplayName: Emil
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2020-07-30T14:51:33.127Z
Answers.Text: There are also papers using Mindstorms to automate a process, making it more consistent than a student with a stopwatch.
Answers.UserDisplayName: Chris H
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2019-04-14T20:38:50.063Z
Answers.LastActivityDate: 2019-04-14T20:38:50.063Z
Answers.UserDisplayName: Joseph Rogers
Answers.Body: <p>Disclaimer: this is cheating a bit.</p>
  
  <hr>
  
  <p><strong>All of them!</strong></p>
  
  <p><a href="https://i.sstatic.net/PtI9v.jpg" rel="noreferrer"><img src="https://i.sstatic.net/PtI9v.jpg" alt="enter image description here"></a></p>
  
  <p>I mean - <a href="https://mashable.com/2017/11/02/lego-airbnb-competition/#_rCwtBTyxsqg" rel="noreferrer">even the most simple lego brick serves as a brick</a>, so a creative mind can devise a real-world use for almost any brick if you have enough time, money and bricks at hand.</p>
  
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2019-04-15T17:38:29.140Z
Answers.LastActivityDate: 2019-04-15T17:38:29.140Z
Answers.UserDisplayName: T. Sar
Answers.Body: <p>I suppose several of the tools in <a href="https://www.bricklink.com/v2/catalog/catalogitem.page?P=6246c01#T=I" rel="nofollow noreferrer">Minifigure utensil wheel</a> theoretically could be used in certain circumstances. I.e. you could hit things with the hammer, it would probably break before you got anything useful done with it, but it can still be said to have it's functionality.</p>
  
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2019-04-13T19:28:28.807Z
Answers.LastActivityDate: 2019-04-13T19:28:28.807Z
Answers.UserDisplayName: Henrik supports the community
Answers.Body: <p>LEGO rubber bands, O-rings, and belts can be used to grip things, for sealing pneumatic moving parts, and for transmitting power.</p>
  
  <p>LEGO sails actually catch wind on floating vessels, and the covered wagon covers and tents keep water off whatever's underneath them.</p>
  
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2019-04-16T19:36:40.853Z
Answers.LastActivityDate: 2019-04-16T19:36:40.853Z
Answers.UserDisplayName: Zemyla
Answers.Body: <p>Robots created with the Mindstorms product line are real robots.</p>
  
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2019-04-29T14:12:12.803Z
Answers.LastActivityDate: 2019-04-29T14:47:39.857Z
Answers.LastEditDate: 2019-04-29T14:47:39.857Z
Answers.UserDisplayName: EndlessVoid
Answers.Body: <p>Ultimately, <em>all</em> functional LEGO elements can be used in the "real world" for their function.</p>
  
  <ul>
  <li>Hinges can be used as hinges</li>
  <li>Wheels work well as wheels</li>
  <li>Containers (e.g. drawers) can contain things</li>
  <li>Magnets work as magnets</li>
  <li>Decorative elements can be used for decoration</li>
  </ul>
  
  <p>... and so on.</p>
  
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2019-04-25T05:41:32.407Z
Answers.Text: They're the most prolific tire manufacturer in the world, twice over.
Answers.UserDisplayName: Mazura
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2019-12-27T21:16:19.390Z
Answers.Text: @Mazura By unit, perhaps. :)
Answers.UserDisplayName: T.J.L.
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2019-04-16T12:15:49.323Z
Answers.LastActivityDate: 2019-04-16T12:21:15.627Z
Answers.LastEditDate: 2019-04-16T12:21:15.627Z
Answers.UserDisplayName: Kramii
Answers.Body: <p>A few lab examples that have used my parts, mainly 80s/90s Technic:</p>
  <ul>
  <li>A quick <a href="https://en.wikipedia.org/wiki/Spin_coating" rel="nofollow noreferrer">spincoater</a> made of Technic for use with microscope slides. (&quot;We need a small spincoater.  Tomorrow.&quot;)</li>
  <li>A syringe pusher using pneumatic Technic.  Unlike pushing by hand the syringe didn't move under the microscope when squeezed.</li>
  </ul>
  <p>Both these two were for a research project; the Lego wasn't mentioned in <a href="https://www.sciencedirect.com/science/article/pii/S0026271414000109" rel="nofollow noreferrer">the paper</a> though.  BTW spin-coating doesn't work well with liquid crystals on structured surfaces, or at least not with the electric field geomtery we had.</p>
  <ul>
  <li>In a teaching lab, spinning Technic plates at 20 000 rpm to look at the Doppler shift of ultrasound reflected off them (not a Lego motor, but the rest was).</li>
  <li>Another teaching project: A Lego model of <a href="https://en.wikipedia.org/wiki/%CA%BBOumuamua" rel="nofollow noreferrer">ʻOumuamua</a> made from various colours of 2x2 round bricks and rotated using Technic.  The reflection of a light source was recorded on a photodiode to simulate observations.</li>
  </ul>
  <p>I've also used Technic to make:</p>
  <ul>
  <li>One-off assembly jigs to hold a workpiece on a funny angle while glue dried (engineering job)</li>
  <li>A large setsquare incorporating a set of <a href="https://en.wikipedia.org/wiki/Iron_sights" rel="nofollow noreferrer">open sights</a> to align a laser beam to the wall in my lab.  Lego+Pythagoras proved squarer than the building.</li>
  </ul>
  <p>Essentially all Technic is potentially useful in the lab, plus other parts as needed to make it fit.</p>
  
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2020-07-30T15:09:30.667Z
Answers.LastActivityDate: 2020-07-30T15:09:30.667Z
Answers.UserDisplayName: Chris H
Answers.Body: <p>As a child, I successfully replaced the perished tyre on the bobbin winder of my mother's sewing machine with a Lego tyre of similar diameter.</p>
  
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2022-08-27T20:15:20.153Z
Answers.LastActivityDate: 2022-08-27T20:15:20.153Z
Answers.UserDisplayName: john_e
Answers.Body: <p>There are several lego &quot;pieces&quot; that function as tools for humans to use with Lego. Most notably the <a href="https://rebrickable.com/parts/96874/brick-and-axle-separator-v20/" rel="nofollow noreferrer">Brick Separator</a> and its variations, but also <a href="https://rebrickable.com/parts/74864/duplo-toolo-tool-screwdriver/" rel="nofollow noreferrer">Duplo Toolo Screwdriver</a> and <a href="https://rebrickable.com/parts/74864c02/duplo-toolo-tool-wrench/" rel="nofollow noreferrer">Wrench</a>, <a href="https://rebrickable.com/parts/upn0199/rc-car-parts-separator-tool-metal/" rel="nofollow noreferrer">RC Car Separator</a>, and <a href="https://rebrickable.com/parts/upn0156/tool-triangle-ruler-20-x-12-x-033/" rel="nofollow noreferrer">Triangle Ruler</a>.</p>
  
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2022-08-26T02:02:45.880Z
Answers.LastActivityDate: 2022-08-26T02:02:45.880Z
Answers.UserDisplayName: Matthew Jensen
Body: <p>I have noticed that there are a few LEGO pieces that also function in the "real-world." For example, the  <a href="https://www.bricklink.com/v2/catalog/catalogitem.page?P=10830c01&amp;name=Minifigure,%20Utensil%20Magnifying%20Glass%20Thick%20Frame%20and%20Solid%20Handle%20with%20Trans-Clear%20Lens&amp;category=%5BMinifigure,%20Utensil%5D#T=C" rel="noreferrer">10830c01 Magnifying Glass</a> can actually magnify. 
  <a href="https://i.sstatic.net/inFLL.jpg" rel="noreferrer"><img src="https://i.sstatic.net/inFLL.jpg" alt="enter image description here"></a></p>
  
  <p>Another example is the <a href="https://www.bricklink.com/v2/catalog/catalogitem.page?P=70001pb01&amp;name=Minifigure,%20Utensil%20Compass%20Pattern&amp;category=%5BMinifigure,%20Utensil,%20Decorated%5D#T=C" rel="noreferrer">70001pb01 Compass</a>, which works the same way you'd expect any "real-world" compass to function. (Although it's not always 100% accurate.)</p>
  
  <p>Are there any other LEGO pieces that have "real-world" functionality?</p>
  
Comments.ContentLicense: CC BY-SA 4.0
Comments.CreationDate: 2019-04-14T03:42:55.043Z
Comments.Text: I realize this question is specific to parts/pieces, but it seems worth noting that there are lots of sets that are useful.  I've been totally happy with my 40173 picture frame.
Comments.UserDisplayName: chicks
Comments.ContentLicense: CC BY-SA 4.0
Comments.CreationDate: 2019-04-14T04:34:58.143Z
Comments.Text: Isn't every item lego makes an effective caltrop when left on the floor?  More-so on hard floors rather than carpet, and damage multiplier for bare-feet.
Comments.UserDisplayName: Criggie
Comments.ContentLicense: CC BY-SA 4.0
Comments.CreationDate: 2019-04-14T08:50:12.533Z
Comments.Text: @Criggie And now imagine an entire floor made of lego...! [Bedtime in a Legohouse](http://youtube.com/watch?v=FrLkHn_RlgY)
Comments.UserDisplayName: Uli
Comments.ContentLicense: CC BY-SA 4.0
Comments.CreationDate: 2019-04-14T16:05:37.003Z
Comments.Text: @Criggie That's probably the "real world" use that I am most familiar with! xD
Comments.UserDisplayName: Magnus
Comments.ContentLicense: CC BY-SA 4.0
Comments.CreationDate: 2019-04-14T16:08:10.907Z
Comments.Text: @chicks That's a great point. If we're talking about sets, then I suppose the LEGO Board Games would be another thing that works in the "real-world!"
Comments.UserDisplayName: Magnus
Comments.ContentLicense: CC BY-SA 4.0
Comments.CreationDate: 2019-04-14T22:50:53.080Z
Comments.Text: This seems way too obvious for it to not to be posted yet, so I must be missing something .... but what about Lego wheels?  They are all .... wheels!  Real, proper, functional wheels!
Comments.UserDisplayName: Moo
Comments.ContentLicense: CC BY-SA 4.0
Comments.CreationDate: 2019-04-15T12:28:27.157Z
Comments.Text: Do you mean real-world functionality or real-world appliances?
Comments.UserDisplayName: yunzen
Comments.ContentLicense: CC BY-SA 4.0
Comments.CreationDate: 2019-04-15T15:14:29.263Z
Comments.Text: https://gizmodo.com/desk-made-entirely-out-of-lego-285777
Comments.UserDisplayName: Joshua
Comments.ContentLicense: CC BY-SA 4.0
Comments.CreationDate: 2019-04-15T15:59:22.337Z
Comments.Text: @yunzen Real-world functionality.
Comments.UserDisplayName: Magnus
Comments.ContentLicense: CC BY-SA 4.0
Comments.CreationDate: 2019-04-15T20:32:29.170Z
Comments.Text: I'm stumped by how you define "real world." Certainly, almost 100% of lego pieces work in the real world? Lego wheels actually turn, hinges actually hinge, doors open, and you can actually make a wall out of plain old lego bricks. I don't see how any of those are really any different than the magnifying glass example.
Comments.UserDisplayName: dwizum
Comments.ContentLicense: CC BY-SA 4.0
Comments.CreationDate: 2019-04-15T21:41:02.690Z
Comments.Text: @dwizum Right, I see what you're saying, but realistically, would a wall of LEGO bricks withstand the weather? Would a house made of LEGO keep you warm? Would LEGO hinges support a door for an extended period of time? Whereas if you needed to magnify small print, a LEGO magnifying glass would work just fine. Although, in all honesty, the line between "real-world" and "not real-world" uses are pretty hazy. :/
Comments.UserDisplayName: Magnus
Comments.ContentLicense: CC BY-SA 4.0
Comments.CreationDate: 2019-04-15T21:51:42.403Z
Comments.Text: @dwizum Oh, and also, I thought I'd add that this question is primarily asking about singular pieces. So one piece by itself can't be a wall for a house or serve as a hinge for a door.
Comments.UserDisplayName: Magnus
Comments.ContentLicense: CC BY-SA 4.0
Comments.CreationDate: 2019-04-16T05:51:19.343Z
Comments.Text: @Magnus: You should edit those clarifications into your question itself.
Comments.UserDisplayName: V2Blast
Comments.ContentLicense: CC BY-SA 4.0
Comments.CreationDate: 2019-04-16T12:34:41.763Z
Comments.Text: I guess my point is, yes a lego wall useful for humans would be impractical, but it seems no different than how useful the magnifying glass would actually be (yes, it magnifies, but it's TINY and would be incredibly awkward and/or frustrating to actually use in a similar manner to how you'd use a normal-sized magnifying glass). I don't want to come off as negative, I think this is a really great question, I'm just struggling because I see "real world functionality" as a spectrum (vs a binary yes/no) in the absence of any specific criteria.
Comments.UserDisplayName: dwizum
Comments.ContentLicense: CC BY-SA 4.0
Comments.CreationDate: 2019-04-16T19:06:05.257Z
Comments.Text: @dwizum I just edited my question to clarify what I'm trying to say. I completely agree that it's more of a spectrum, so I added that to the end. And no worries, you're not coming off as negative, I appreciate how you are making me think deeper into this question and the underlying idea. :)
Comments.UserDisplayName: Magnus
Comments.ContentLicense: CC BY-SA 4.0
Comments.CreationDate: 2019-04-16T19:06:45.997Z
Comments.Text: @V2Blast You're right. I just went ahead and made that edit.
Comments.UserDisplayName: Magnus
Tags: <piece-information>
Title: What LEGO pieces have "real-world" functionality?
UserDisplayName: Magnus
ThreadText: # What LEGO pieces have "real-world" functionality?
  
  (Asked by: username_0 on 2019-04-13)
  
  I have noticed that there are a few LEGO pieces that also function in the "real-world." For example, the [10830c01 Magnifying Glass](https://www.bricklink.com/v2/catalog/catalogitem.page?P=10830c01&name=Minifigure,%20Utensil%20Magnifying%20Glass%20Thick%20Frame%20and%20Solid%20Handle%20with%20Trans-Clear%20Lens&category=%5BMinifigure,%20Utensil%5D#T=C) can actually magnify.
  [![enter image description here](https://i.sstatic.net/inFLL.jpg)](https://i.sstatic.net/inFLL.jpg)
  
  Another example is the [70001pb01 Compass](https://www.bricklink.com/v2/catalog/catalogitem.page?P=70001pb01&name=Minifigure,%20Utensil%20Compass%20Pattern&category=%5BMinifigure,%20Utensil,%20Decorated%5D#T=C), which works the same way you'd expect any "real-world" compass to function. (Although it's not always 100% accurate.)
  
  Are there any other LEGO pieces that have "real-world" functionality?
  
  **Tags:** piece-information
  
  > **Comments:**
  > **username_1**: I realize this question is specific to parts/pieces, but it seems worth noting that there are lots of sets that are useful.  I've been totally happy with my 40173 picture frame.  
  > **username_2**: Isn't every item lego makes an effective caltrop when left on the floor?  More-so on hard floors rather than carpet, and damage multiplier for bare-feet.  
  > **username_3**: @username_2 And now imagine an entire floor made of lego...! [Bedtime in a Legohouse](http://youtube.com/watch?v=FrLkHn_RlgY)  
  > **username_0**: @username_2 That's probably the "real world" use that I am most familiar with! xD  
  > **username_0**: @username_1 That's a great point. If we're talking about sets, then I suppose the LEGO Board Games would be another thing that works in the "real-world!"  
  > **username_4**: This seems way too obvious for it to not to be posted yet, so I must be missing something .... but what about Lego wheels?  They are all .... wheels!  Real, proper, functional wheels!  
  > **username_5**: Do you mean real-world functionality or real-world appliances?  
  > **username_6**: https://gizmodo.com/desk-made-entirely-out-of-lego-285777  
  > **username_0**: @username_5 Real-world functionality.  
  > **username_7**: I'm stumped by how you define "real world." Certainly, almost 100% of lego pieces work in the real world? Lego wheels actually turn, hinges actually hinge, doors open, and you can actually make a wall out of plain old lego bricks. I don't see how any of those are really any different than the magnifying glass example.  
  > **username_0**: @username_7 Right, I see what you're saying, but realistically, would a wall of LEGO bricks withstand the weather? Would a house made of LEGO keep you warm? Would LEGO hinges support a door for an extended period of time? Whereas if you needed to magnify small print, a LEGO magnifying glass would work just fine. Although, in all honesty, the line between "real-world" and "not real-world" uses are pretty hazy. :/  
  > **username_0**: @username_7 Oh, and also, I thought I'd add that this question is primarily asking about singular pieces. So one piece by itself can't be a wall for a house or serve as a hinge for a door.  
  > **username_8**: @username_0: You should edit those clarifications into your question itself.  
  > **username_7**: I guess my point is, yes a lego wall useful for humans would be impractical, but it seems no different than how useful the magnifying glass would actually be (yes, it magnifies, but it's TINY and would be incredibly awkward and/or frustrating to actually use in a similar manner to how you'd use a normal-sized magnifying glass). I don't want to come off as negative, I think this is a really great question, I'm just struggling because I see "real world functionality" as a spectrum (vs a binary yes/no) in the absence of any specific criteria.  
  > **username_0**: @username_7 I just edited my question to clarify what I'm trying to say. I completely agree that it's more of a spectrum, so I added that to the end. And no worries, you're not coming off as negative, I appreciate how you are making me think deeper into this question and the underlying idea. :)  
  > **username_0**: @username_8 You're right. I just went ahead and made that edit.  
  
  ---
  
  ## 16 answers
  
  ### Answer by username_9 on 2019-04-15. Score: 18 | Accepted answer
  
  The [web pieces made of flexible string](https://www.bricklink.com/v2/catalog/catalogitem.page?P=71155#T=C) are perfectly serviceable real-life webs, even if they are too small for most applications.
  
  Of course the LEGO brand [magnets](https://rebrickable.com/parts/73092/magnet-cylindrical/) are working real-life magnets as well.
  
  Some sets have included large [air bellows](https://brickset.com/parts/design-76543) that could be compressed manually (i.e. hit) to supply a burst of air to launch a projectile or a [racecar](https://brickset.com/parts/design-87945).
  
  The [light-up bricks](https://brickset.com/parts/design-98785) are naturally serviceable as tiny flashlights.
  
  The [rechargeable](https://brickset.com/sets/8878-1/Rechargeable-Battery-Box) [batteries](https://brickset.com/parts/design-19106) are usable outside of the LEGO world as batteries.
  
  The [large sawblade](https://brickset.com/parts/design-61403) used in some constructible action figure lines (for example [Bionicle](https://brickset.com/sets/71312-1/Ekimu-the-Mask-Maker)) and System lines (for example [Power Miners](https://brickset.com/sets/8963-1/Rock-Wrecker)) with the right setup could be used as a table saw to cut through paper or other materials of comparable strength.
  
  The [parachutes](https://brickset.com/parts/design-43364) of the 2019 City Police sets are advertiesed as working parachutes, so I'd expect them to be ... working parachutes, at least for loads comparable to minifigures.
  
  Almost all LEGO [propeller](https://brickset.com/parts/design-6041) pieces are functional propellers (having pitch and accepting an axle), with admittedly terrible performance compared to purpose-engineered examples.
  
  The [old-style 9V](https://brickset.com/sets/5311-1/Two-2-x-2-Plates-with-Wire-25-6-cm) and newer [PF electric extension wires](https://brickset.com/parts/design-21655) could be used as real wires.
  
  The [electrical switches](https://brickset.com/parts/design-61929) (or polarity changers) are working too.
  
  In the same vein, the pneumatic components ([pump](https://brickset.com/parts/design-74982), [tube](https://brickset.com/parts/design-88355), [valve](https://brickset.com/parts/design-19474), [cylinder](https://brickset.com/parts/design-19475), [tank](https://brickset.com/parts/design-75974), [manometer](http://www.brickfactory.info/scans/0009000/9641/030.jpg)) are working as well.
  
  The Technic [shock absorbers](https://brickset.com/parts/design-76537) (springs) would apply too, some are even [adjustable](https://brickset.com/parts/design-47373).
  
  Naturally, all Technic [gears](https://brickset.com/parts/category-Technic/tag-Gear?query=gear) are working gears, even if they have suboptimal shapes and materials compared to real-world examples.
  
  The LEGO City [mugs](https://brickset.com/parts/design-10035) can actually hold tiny amounts of liquids.
  
  The [boat](https://brickset.com/parts/design-2551) [hull](https://brickset.com/parts/design-28925) [pieces](https://brickset.com/parts/design-62792) that are advertised as being able to float, do of course float.
  
  The treasure chest, large barrel and letterbox pieces are tiny, but functional storage items.
  
  Some City sets include working car jacks.
  
  LEGO has produced mirror pieces with stickers that really reflect light and of course all transparent window panels let light through. On the same topic, many door elements have working hinges and the tiny fences could be used to separate tiny gardens and to keep tiny animals from crossing over. (Caveat: almost all animals that are small enough that can't just step over it can probably climb over or fit through the holes)
  
  Possibly the most boring example of all: the [weighted brick](https://brickset.com/parts/design-73843) does indeed weight quite a lot due to a metal insert and is thus usable as counterweight.
  
  > **Comments:**
  > **username_10**: Not sure the boat hull pieces really count - I mean, LEGOs are made of plastic, and thus _all_ float (possible exception of the weighted brick).  Being boat hull-shaped does not necessarily make any difference in that respect...  
  > **username_9**: @username_10 Certainly not all bricks float and lots of them do so only as long as the air bubbles trapped on the underside are not dissolved in the water. See for example: https://bricks.stackexchange.com/a/9013/3631  
  
  ---
  
  ### Answer by username_3 on 2019-04-14. Score: 48
  
  ## All Aboard!
  
  I'd like to add my all-time favorite LEGO piece:
  
  * x870cc02, **THE BLACK WHISTLE!**
  
  [![enter image description here](https://i.sstatic.net/uIlbe.jpg)](https://i.sstatic.net/uIlbe.jpg)
  
  The white brick is a microphone. Attach it to your train's motor and **BLOW THAT WHISTLE**! Depending on how short (or LONG!) your whistling was, the train would go forwards or backwards.
  
  * Real-world use: Not only did it drive your train round the bend, **but your parents too...!**
  
  > **Comments:**
  > **username_11**: You got two awesome items in one post!. The microphone is awesome too!  
  
  ---
  
  ### Answer by username_18 on 2019-04-16. Score: 24
  
  Minifig accessory "shovel" can be used for dispensing minute amounts of a powder. Urban legend attributes such usage to drug dealers.
  
  The fact that [amazon lists](https://rads.stackoverflow.com/amzn/click/com/B00K2BP8Q8) digital pocket scale (0,1 g resolution, 100g max) and an airtight container as "frequently bought together" hints it's more than just a legend and LEGO shovels are indeed used in this way.
  
  [![printscreen](https://i.sstatic.net/cf7tj.png)](https://i.sstatic.net/cf7tj.png)
  
  > **Comments:**
  > **username_12**: This is the best answer. Welcome to Bricks.SE.  
  > **username_12**: Look at the insane price for the shovel! Bricklink lists it as [Minifigure, Utensil Shovel (Round Stem End)](https://www.bricklink.com/v2/catalog/catalogitem.page?P=3837&name=Minifigure,%20Utensil%20Shovel%20(Round%20Stem%20End)&category=%5BMinifigure,%20Utensil%5D#T=S&O={%22iconly%22:0}), not to be confused with the much more expensive [Minifigure, Utensil Shovel (Flat Stem End)](https://www.bricklink.com/v2/catalog/catalogitem.page?P=88431&name=Minifigure,%20Utensil%20Shovel%20(Flat%20Stem%20End)&category=%5BMinifigure,%20Utensil%5D#T=S&O={%22iconly%22:0}).  
  > **username_18**: @Aziraphale When you're weighting a powder that's worth $100 per gram, $4.69 is reasonable investment : )  
  > **username_19**: If anyone are interested, I can probably find some of those shovels to sell for $4.00 (that's a discount on several times the average price on bricklink for those).  
  > **username_17**: Now the link says "page not found"  
  > **username_18**: @username_17 Thanks, that's why I put the screenshot.  
  
  ---
  
  ### Answer by username_20 on 2019-04-14. Score: 20
  
  The holes in Lego Technic work very well as holes.
  
  By which I mean, I have built very successful motor-driven cross slides for small machine tools using Technic pieces.
  
  When paired with nominally 4.8mm metric ground rod (which tends to have a negative tolerance) the 4.8mm holes are a nice sliding fit. Imperial 3/16" rod at about 4.76mm also works, but is a bit sloppier.
  
  Although the hole is a little undersized for tapping M6 (5.0 required), the soft plastic easily allows a taper tap to be run through. The 1mm pitch of the thread, together with the hard metric 8mm width of the brick means that the start and finish phase of the threads is identical. If an already tapped brick is pegged as a guide to a new brick, then (a) the guide will help ensure that thread goes in straight and (b) has the same phase in both bricks. I mark a guide brick, so there's no cummulative error in creating new tapped bricks.
  
  A piece of 6mm studding can then be used as a lead screw. It can be fitted concentrically to Technic shafts by locknutting it to a tapped brick, then pegging the brick to a 40t gear.
  
  That's all been taken apart now. But only last week I had a measurement problem, and needed to be able to adjust the height of a stage quickly between many, repeatable, fairly precise heights. Behold, two sets of binary stacking gauge blocks, 16x8mm down to 1x8mm.
  
  [![enter image description here](https://i.sstatic.net/v35DV.jpg)](https://i.sstatic.net/v35DV.jpg)
  
  > **Comments:**
  > **username_8**: "Technic", not "Technik". (I don't know if there's anything else to fix in your answer, or I'd edit the fix in myself.)  
  
  ---
  
  ### Answer by username_21 on 2019-04-14. Score: 19
  
  I once published a paper in a peer reviewed scientific journal using data gathered using a remote translation stage constructed from Lego Technic.
  
  I could only get ~ +-1mm accuracy out of it, where the proper stages were more like +- 0.1mm, but it was good enough for a proof of concept and the proper stages were on back order.
  
  Of course many people would say that an X-Ray Physics lab is not the real world, but that's another matter!
  
  > **Comments:**
  > **username_22**: citation needed ;-)  
  > **username_21**: lol, this is the paper https://scripts.iucr.org/cgi-bin/paper?aj5138, but oddly enough I didn't mention what the translation stage was made from in the text!  
  > **username_22**: non-paywalled paper, where I can almost see the stage moving along the axis in Figure 1.  https://ore.exeter.ac.uk/repository/bitstream/handle/10871/22169/X-ray%20diffraction%20from%20bone%20employing.pdf?sequence=1 Speaking of X-rays and tracks, you may also like [Where (if anywhere) were X-ray machines put on trains or trolleys to image “Everybody over 14 years old”?](https://history.stackexchange.com/q/50628/33008)  
  > **username_21**: nice find, that's actually a different paper from the same research group but it's the same geometry being exploited, that one's from after I left the group so they'll have been using proper equipment by then (so was I after the very first PoC experiments)  
  > **username_23**: Another scientific experiment that uses Lego is the [squeezed light](https://en.wikipedia.org/wiki/Squeezed_states_of_light) source of the gravitational-wave detector GEO600, which uses black Lego bricks for stray light baffles in its optical assembly. Here's an old [video documentary](https://youtu.be/nYaDW43aHa0?t=78)   (in German) where two of the scientists test the best colour to use and you can see the finished result on p. 82 of this [thesis](https://doi.org/10.15488/7661) (if you look closely).  
  > **username_24**: There are also papers using Mindstorms to automate a process, making it more consistent than a student with a stopwatch.  
  
  ---
  
  ### Answer by username_12 on 2019-04-13. Score: 16
  
  One obvious answer is all components of the power functions family. [![all components of the power functions family](https://i.sstatic.net/tRBSY.jpg)](https://i.sstatic.net/tRBSY.jpg)
  
  Lights can be used as lights, motors can be used as motors.
  
  
  ---
  
  ### Answer by username_13 on 2019-04-15. Score: 8
  
  Gears function quite well for creating mechanical devices such as functioning clocks:
  
  [![KEvronista skeleton clock](https://i.sstatic.net/jEmJA.jpg)](https://i.sstatic.net/jEmJA.jpg)
  [Design by KEvronista](https://www.youtube.com/watch?v=O-h6MMkNL_w), picture by me.
  
  Naturally you can use an electric motor for more accurate timekeeping, as in the NXT Classic Clock (bonus model from Lego):
  
  [![Screenshot of NXT Classic CLock](https://i.sstatic.net/x2LBi.png)](https://i.sstatic.net/x2LBi.png)
  
  ---
  
  LEGO Mindstorms robotics kits are also a great way for kids and adults to get started with robotics, and I would bet that a good number of current robotics and mechanical engineers got their start with building LEGO robots. There's a healthy educational community and competitions such as FIRST Robotics.
  
  
  ---
  
  ### Answer by username_14 on 2019-04-14. Score: 8
  
  Those shoehorn pieces worked. Technically, all of them serve their intended purpose as bricks. The ropes function. The ball shooting contraption present in the Lego Ninjago dragons (and other sets, I bet) functioned, as well as the spring-loaded cannon pieces. The axles technically worked (but not very well in actual cars).
  
  > **Comments:**
  > **username_15**: I've seen them serve [their 'intended' purpose](https://seenaroundboston.com/wp-content/uploads/2016/05/lego-patch-hole-in-brick-wall-642x482.jpg) in the real world. My favorite piece though: **the winch**.  
  > **username_9**: What do you mean by "Those shoehorn pieces"?  
  > **username_16**: The brick puller?  
  > **username_17**: @username_15 My antivirus says that webpage is dangerous.  
  > **username_15**: @username_17 - mine too. It's a picture where someone used a bunch to tuck point some missing (actual) bricks on the corner of a house.  
  
  ---
  
  ### Answer by username_25 on 2019-04-15. Score: 5
  
  Disclaimer: this is cheating a bit.
  
  ---
  
  **All of them!**
  
  [![enter image description here](https://i.sstatic.net/PtI9v.jpg)](https://i.sstatic.net/PtI9v.jpg)
  
  I mean - [even the most simple lego brick serves as a brick](https://mashable.com/2017/11/02/lego-airbnb-competition/#_rCwtBTyxsqg), so a creative mind can devise a real-world use for almost any brick if you have enough time, money and bricks at hand.
  
  
  ---
  
  ### Answer by username_19 on 2019-04-13. Score: 4
  
  I suppose several of the tools in [Minifigure utensil wheel](https://www.bricklink.com/v2/catalog/catalogitem.page?P=6246c01#T=I) theoretically could be used in certain circumstances. I.e. you could hit things with the hammer, it would probably break before you got anything useful done with it, but it can still be said to have it's functionality.
  
  
  ---
  
  ### Answer by username_26 on 2019-04-16. Score: 4
  
  LEGO rubber bands, O-rings, and belts can be used to grip things, for sealing pneumatic moving parts, and for transmitting power.
  
  LEGO sails actually catch wind on floating vessels, and the covered wagon covers and tents keep water off whatever's underneath them.
  
  
  ---
  
  ### Answer by username_27 on 2019-04-29. Score: 4
  
  Robots created with the Mindstorms product line are real robots.
  
  
  ---
  
  ### Answer by username_28 on 2019-04-16. Score: 4
  
  Ultimately, *all* functional LEGO elements can be used in the "real world" for their function.
  
  * Hinges can be used as hinges
  * Wheels work well as wheels
  * Containers (e.g. drawers) can contain things
  * Magnets work as magnets
  * Decorative elements can be used for decoration
  
  ... and so on.
  
  > **Comments:**
  > **username_15**: They're the most prolific tire manufacturer in the world, twice over.  
  > **username_29**: @username_15 By unit, perhaps. :)  
  
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  ### Answer by username_24 on 2020-07-30. Score: 3
  
  A few lab examples that have used my parts, mainly 80s/90s Technic:
  
  * A quick [spincoater](https://en.wikipedia.org/wiki/Spin_coating) made of Technic for use with microscope slides. ("We need a small spincoater. Tomorrow.")
  * A syringe pusher using pneumatic Technic. Unlike pushing by hand the syringe didn't move under the microscope when squeezed.
  
  Both these two were for a research project; the Lego wasn't mentioned in [the paper](https://www.sciencedirect.com/science/article/pii/S0026271414000109) though. BTW spin-coating doesn't work well with liquid crystals on structured surfaces, or at least not with the electric field geomtery we had.
  
  * In a teaching lab, spinning Technic plates at 20 000 rpm to look at the Doppler shift of ultrasound reflected off them (not a Lego motor, but the rest was).
  * Another teaching project: A Lego model of [ʻOumuamua](https://en.wikipedia.org/wiki/%CA%BBOumuamua) made from various colours of 2x2 round bricks and rotated using Technic. The reflection of a light source was recorded on a photodiode to simulate observations.
  
  I've also used Technic to make:
  
  * One-off assembly jigs to hold a workpiece on a funny angle while glue dried (engineering job)
  * A large setsquare incorporating a set of [open sights](https://en.wikipedia.org/wiki/Iron_sights) to align a laser beam to the wall in my lab. Lego+Pythagoras proved squarer than the building.
  
  Essentially all Technic is potentially useful in the lab, plus other parts as needed to make it fit.
  
  
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  ### Answer by username_30 on 2022-08-27. Score: 2
  
  As a child, I successfully replaced the perished tyre on the bobbin winder of my mother's sewing machine with a Lego tyre of similar diameter.
  
  
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  ### Answer by username_31 on 2022-08-26. Score: 2
  
  There are several lego "pieces" that function as tools for humans to use with Lego. Most notably the [Brick Separator](https://rebrickable.com/parts/96874/brick-and-axle-separator-v20/) and its variations, but also [Duplo Toolo Screwdriver](https://rebrickable.com/parts/74864/duplo-toolo-tool-screwdriver/) and [Wrench](https://rebrickable.com/parts/74864c02/duplo-toolo-tool-wrench/), [RC Car Separator](https://rebrickable.com/parts/upn0199/rc-car-parts-separator-tool-metal/), and [Triangle Ruler](https://rebrickable.com/parts/upn0156/tool-triangle-ruler-20-x-12-x-033/).
  
  
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