# Washers and Bolts

**URL:** <https://boards.straightdope.com/t/washers-and-bolts/310222>\
**Category:** Cecil's Columns/Staff Reports\
**Created:** [June 28, 2005, 4:48pm UTC](https://boards.straightdope.com/t/washers-and-bolts/310222 "2005-06-28T16:48:30Z")\
**Posts on this page:** 4\
**Page:** 1

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**Author:** ![aerodave](https://avatars.discourse-cdn.com/v4/letter/a/f08c70/32.png) [@aerodave](https://boards.straightdope.com/u/aerodave)\
**Post date:** [June 28, 2005, 4:48pm UTC](https://boards.straightdope.com/t/washers-and-bolts/310222/1 "2005-06-28T16:48:30Z")

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First off, let me say that I particularly love Una’s reports, because they’re always about gearhead stuff. The engineer in me prefers these kinds of articles to the historical ones.

However, I wonder if I should nit-pick just a little regarding today’s Staff Report:

[http://www.straightdope.com/mailbag/mwasher.html](http://www.straightdope.com/mailbag/mwasher.html)

Specifically, this statement bothers me:

> [@Una](#):
>
> Bolts (or nuts and threaded shafts) work by placing the fastened parts under tension.

To me, it seems more proper to say it is the _bolt_ that is under tension, as it is stretched by having been tightened. What balances this is the resistance of the joined parts, which are put under _compression_. Both compression and tension play into a fastened joint (they must come as a pair in order to maintain static equilibrium). But again, I think the fastened parts would be more accurately described as being in compression.

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**Author:** ![aerodave](https://avatars.discourse-cdn.com/v4/letter/a/f08c70/32.png) [@aerodave](https://boards.straightdope.com/u/aerodave)\
**Post date:** [June 28, 2005, 4:54pm UTC](https://boards.straightdope.com/t/washers-and-bolts/310222/2 "2005-06-28T16:54:13Z")

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I just realized I made a redundant thread. I looked down the list and swore this one hadn’t been commented on.

If the mods would like to merge my comment into the original thread, I’d think that was awesome.

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**Author:** ![Una\_Persson](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/una_persson/32/346_2.png) [@Una\_Persson](https://boards.straightdope.com/u/Una_Persson)\
**Post date:** [June 28, 2005, 8:41pm UTC](https://boards.straightdope.com/t/washers-and-bolts/310222/3 "2005-06-28T20:41:35Z")

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You are correct, that part is worded wrong. It was a result of editing from my report to the Web. The original report said this:

> [@](#):
>
> In high-stress fastening and joining applications, bolts (or nuts and threaded shafts) work by being placed under tension by tightening the nut or bolt head, applying stress to hold together the parts that the shaft passes through. This tension, or preloading, is very important for giving strength to the joint and for reducing the fatigue of the bolt due to fluctuating (variable) loads – such as in a machine part, like an engine.

Sadly, I was out of the country last week without any net access to speak of, and wasn’t around to check things in the transition. I’ll have to see if we can fix that part of the text shortly.

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**Author:** ![C\_K\_Dexter\_Haven](https://avatars.discourse-cdn.com/v4/letter/c/b2d939/32.png) [@C\_K\_Dexter\_Haven](https://boards.straightdope.com/u/C_K_Dexter_Haven)\
**Post date:** [June 28, 2005, 11:40pm UTC](https://boards.straightdope.com/t/washers-and-bolts/310222/4 "2005-06-28T23:40:51Z")

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Lemme suggest we all use this thread: [http://boards.straightdope.com/sdmb/showthread.php?t=322586](http://boards.straightdope.com/sdmb/showthread.php?t=322586)  
to cover this…