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[TowerTalk] Bolt trivia

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Subject: [TowerTalk] Bolt trivia
From: (Dale Martin)
Date: Sun, 16 Mar 1997 07:18:12 -0600
On Thursday, March 13, 1997 11:25 AM, wrote:
>In a message dated 97-03-13 15:24:18 EST, writes:
>> Why does Rohn (and presumably other tower manufacturers) spec the tower
>>  bolts on their assembly drawings to be "inserted out (i.e. with nuts on
>>  outside of tower face)" ?????
>>  I have always put the nuts on the inside of the tower so that there is
>>  less to snag myself on while climbing the tower.  It seems hard to believe
>>  that that strength is affected by which side of the tower the bolt head
>>  is on versus the nut!!!!
>Terry --
>      When you're building a tower, the saying for bolts is that they all go
>"up and out".  In other words, the bolts either are installed up or out.  
>      While this is an industry practice, I'm not sure of all the reasons.
> You've got to remember that most towers are NOT 25G and 45G.  Many of them
>have angle legs and many internal braces.  If you installed the bolts inward
>on the angle legs, the ends of the bolts would meet/collide and you wouldn't
>be able to get the nuts on them or tighten them very easily.  By putting the
>bolts through so they stick "out", lockwasher and nut attachment is easy and
>there is no hardware interference.  Any ironworkers out there to shed more
>light on this?
>     I also install the bolts on 25G and 45G facing in.  I don't think
>there's an engineering reason why that's a bad idea.  I don't think it's a
>matter of strength, just practicality.
>73,  Steve  K7LXC    
>FAQ on WWW:     
>Administrative requests:
>Sponsored by:             Akorn Access, Inc. & N4VJ / K4AAA

Steve and all,
I am not an engineer, but it seems to me that if the head of the 
bolt is out, then it's more likely that the bolt will be the active element
in the tightening/loosening of the bolt/nut combination.  Its rotation
in the hole(s)  might cause galling of the holes through which the bolt 
is placed and/or galling of the bolt threads.  With the nut out, the nut 
is the active element in that process and the bolt is held static. 



Dale Martin, KG5U

FAQ on WWW:     
Administrative requests:
Sponsored by:             Akorn Access, Inc. & N4VJ / K4AAA

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