# Why did the Angstrom fall out of favor as a unit of measurement?

**URL:** <https://boards.straightdope.com/t/why-did-the-angstrom-fall-out-of-favor-as-a-unit-of-measurement/332356>\
**Category:** Factual Questions\
**Created:** [November 23, 2005, 12:50am UTC](https://boards.straightdope.com/t/why-did-the-angstrom-fall-out-of-favor-as-a-unit-of-measurement/332356 "2005-11-23T00:50:26Z")\
**Posts on this page:** 3\
**Page:** 3

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**Author:** ![David\_Simmons](https://avatars.discourse-cdn.com/v4/letter/d/9de053/32.png) [@David\_Simmons](https://boards.straightdope.com/u/David_Simmons)\
**Post date:** [November 24, 2005, 12:15am UTC](https://boards.straightdope.com/t/why-did-the-angstrom-fall-out-of-favor-as-a-unit-of-measurement/332356/41 "2005-11-24T00:15:53Z")

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> [@robby](#):
>
> That’s not true. The U.S. Customary System (USCS) is still used by most engineers in the U.S. In this system, the unit for force is the pound-force (lbf) and the unit for mass is the pound-mass (lbm). I’ve never seen slugs used in engineering.

:We never used anything for mass but slugs. Equal to the weight in pounds on the earth’s surface divided by the acceleration of gravity.

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**Author:** ![LouisB](https://avatars.discourse-cdn.com/v4/letter/l/dfb087/32.png) [@LouisB](https://boards.straightdope.com/u/LouisB)\
**Post date:** [November 24, 2005, 12:19am UTC](https://boards.straightdope.com/t/why-did-the-angstrom-fall-out-of-favor-as-a-unit-of-measurement/332356/42 "2005-11-24T00:19:04Z")

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I used Angstroms in calculating the frequency shift of a quartz crystal vs the thickness of electrodes. And vice versa.

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**Author:** ![NE\_Texan](https://avatars.discourse-cdn.com/v4/letter/n/e99b99/32.png) [@NE\_Texan](https://boards.straightdope.com/u/NE_Texan)\
**Post date:** [November 24, 2005, 4:34am UTC](https://boards.straightdope.com/t/why-did-the-angstrom-fall-out-of-favor-as-a-unit-of-measurement/332356/43 "2005-11-24T04:34:04Z")

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> [@gazpacho](#):
>
> Really? I work in the chip business all I every see now is nm down from um a few years ago.

Yeah, I’m in the chip business, too. Circuit widths and sizes are nm, but some film thicknesses it’s more convenient to use Angstroms. Not that conversion’s a big deal, it’s just a factor of 10.

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