# How strong is a carbon nanotube? **URL:** \ **Category:** Factual Questions\ **Created:** [May 24, 2005, 10:03pm UTC](https://boards.straightdope.com/t/how-strong-is-a-carbon-nanotube/305339 "2005-05-24T22:03:30Z")\ **Posts on this page:** 9\ **Page:** 1
**Author:** ![The\_Controvert](https://avatars.discourse-cdn.com/v4/letter/t/dec6dc/32.png) [@The\_Controvert](https://boards.straightdope.com/u/The_Controvert)\ **Post date:** [May 24, 2005, 10:03pm UTC](https://boards.straightdope.com/t/how-strong-is-a-carbon-nanotube/305339/1 "2005-05-24T22:03:30Z")
Supposing I had a single strand of carbon nanotube. Would it be visible to the naked eye? Could I pick it up with my hands? Could I tie it to a paper clip and lift it? ---
**Author:** ![Mangetout](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/mangetout/32/19_2.png) [@Mangetout](https://boards.straightdope.com/u/Mangetout)\ **Post date:** [May 24, 2005, 10:39pm UTC](https://boards.straightdope.com/t/how-strong-is-a-carbon-nanotube/305339/2 "2005-05-24T22:39:19Z")
According to this [Wikipedia](http://en.wikipedia.org/wiki/Nanotube) article, they’re really, really small - one ten-thousandth of the thickness of a human hair, or thereabouts; you’re not going to see a single, straight strand; not a chance of it. if you had a few hundred metres of the stuff coiled up in a little container, you might be able to see it (my guess is it would look like smoke). Can’t find any specifics about the strength of a single tube (someone will no doubt be a long in a sec with that data), but if it was strong enough to use as an ordinary thread, I think you’d cut yourself trying to handle it. ---
**Author:** ![MikeS](https://avatars.discourse-cdn.com/v4/letter/m/919ad9/32.png) [@MikeS](https://boards.straightdope.com/u/MikeS)\ **Post date:** [May 25, 2005, 1:47am UTC](https://boards.straightdope.com/t/how-strong-is-a-carbon-nanotube/305339/3 "2005-05-25T01:47:18Z")
> [@The Controvert](#): > > Could I tie it to a paper clip and lift it? No. From **Mangetout** ’s Wikipedia article, the highest measured tensile strength of a nanotube was about 6.3_10[sup]10[/sup] N/m[sup]2[/sup], i.e. a nanotube with a cross-sectional area of one square metre could exert a force of 63 billion Newtons (about 14 billion pounds.) Unfortunately, these things are exceedingly small: their cross-sectional area is on the order of 10[sup]-18[/sup] square meters instead. Working through the numbers, we find a maximum force for a single nanotube on the order of 6.3_10[sup]-8[/sup] Newtons. For comparison, the weight of an average grain of sand is about a thousand times greater than this. A nanotube could easily support an average cell in the human body, though, if it’s any consolation. ---
**Author:** ![spinky](https://avatars.discourse-cdn.com/v4/letter/s/59ef9b/32.png) [@spinky](https://boards.straightdope.com/u/spinky)\ **Post date:** [May 25, 2005, 8:09am UTC](https://boards.straightdope.com/t/how-strong-is-a-carbon-nanotube/305339/4 "2005-05-25T08:09:36Z")
So what about nanotube structures similar in size to a human hair? How much weight could they hold? I don’t imagine you can just scale the numbers up based on cross-sectional area, could you? Would such a structure simply be a braid of thousands of individual nanotubes? ---
**Author:** ![scm1001](https://avatars.discourse-cdn.com/v4/letter/s/c4cdca/32.png) [@scm1001](https://boards.straightdope.com/u/scm1001)\ **Post date:** [May 25, 2005, 8:26pm UTC](https://boards.straightdope.com/t/how-strong-is-a-carbon-nanotube/305339/5 "2005-05-25T20:26:45Z")
nanotubes are getting longer. Here is Cambridge they are made cm long, and harvested from the catalyst surface, like mowing grass, with a razor blade. While an individual nanotube is very strong, it is the strength of the composite structure it is put into that matters, and that is dependent on many factors ---
**Author:** ![Peter\_Morris](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/peter_morris/32/359_2.png) [@Peter\_Morris](https://boards.straightdope.com/u/Peter_Morris)\ **Post date:** [May 26, 2005, 12:49am UTC](https://boards.straightdope.com/t/how-strong-is-a-carbon-nanotube/305339/6 "2005-05-26T00:49:42Z")
> [@MikeS](#): > > A nanotube could easily support an average cell in the human body, though, if it’s any consolation. And these are supposed to hold up the Space Elevator? ---
**Author:** ![Bryan\_Ekers](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/bryan_ekers/32/183_2.png) [@Bryan\_Ekers](https://boards.straightdope.com/u/Bryan_Ekers)\ **Post date:** [May 26, 2005, 3:32am UTC](https://boards.straightdope.com/t/how-strong-is-a-carbon-nanotube/305339/7 "2005-05-26T03:32:17Z")
> [@Peter Morris](#): > > And these are supposed to hold up the Space Elevator? I expect they’ll use more than one. ---
**Author:** ![spinky](https://avatars.discourse-cdn.com/v4/letter/s/59ef9b/32.png) [@spinky](https://boards.straightdope.com/u/spinky)\ **Post date:** [May 31, 2005, 9:36am UTC](https://boards.straightdope.com/t/how-strong-is-a-carbon-nanotube/305339/8 "2005-05-31T09:36:27Z")
> [@](#): > > So what about nanotube structures similar in size to a human hair? How much weight could they hold? Anyone? ---
**Author:** ![AndrewL](https://avatars.discourse-cdn.com/v4/letter/a/3d9bf3/32.png) [@AndrewL](https://boards.straightdope.com/u/AndrewL)\ **Post date:** [May 31, 2005, 1:00pm UTC](https://boards.straightdope.com/t/how-strong-is-a-carbon-nanotube/305339/9 "2005-05-31T13:00:29Z")
> [@ntucker](#): > > Anyone? Using a estimated tensile strength of 130GPa and a width for the human hair of .001 inch, I get about 15 pounds.