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Re: [TowerTalk] FW: UST bolt Torque question

To: "Mitchell, Dennis C" <dmitchell@alionscience.com>
Subject: Re: [TowerTalk] FW: UST bolt Torque question
From: Grant Saviers <grants2@pacbell.net>
Date: Tue, 25 Jun 2013 16:32:49 -0700
List-post: <towertalk@contesting.com">mailto:towertalk@contesting.com>
One leg of a self supporting tower falls "up" - it fails in tension.
My nuts are tight after torquing bolts to 140 ft-lbs...

Grant KZ1W


On 6/25/2013 12:59 PM, Mitchell, Dennis C wrote:
"I've never seen a Tower fall UP."
I'd only torque bolts enough to keep your nuts from falling off...

K8UR


-----Original Message-----
From: TowerTalk [mailto:towertalk-bounces@contesting.com] On Behalf Of KM5VI
Sent: Tuesday, June 25, 2013 3:28 PM
To: towertalk@contesting.com
Subject: [TowerTalk] FW: UST bolt Torque question

Snug tight is a standard term commonly used in the design of bolted connections 
that are not slip-critical.  Slip-critical connections rely on the friction 
created by the clamping action of the threaded connection and require a minimum 
fastener torque or bolt stretch specification to achieve the design friction 
value.  Bolted connection design based on the simple shear and/or bearing 
strength of the fastener do not rely on joint friction, and thus the assembly 
torque is non-critical provided that it is tight enough to eliminate slop in 
the joint that might over time from load cycles (bolt loosening).

FYI - I have found a spud wrench useful for snug tight connections on my 
crank-up tower base connections - it is a short wrench that is designed to be 
struck with a hammer.

Hope this helps.

Matt
KM5VI








-----Original Message-----
From: TowerTalk [mailto:towertalk-bounces@contesting.com] On Behalf Of Jim 
Thomson
Sent: Tuesday, June 25, 2013 7:39 AM
To: towertalk@contesting.com
Subject: [TowerTalk] UST bolt Torque question


I asked UST  how much Torque should be used on both the 12 x  1.125 inch anchor 
rods....and also the 18 x  1 inch leg bolts.
I also told em I used never seize on both anchor rods and legs bolts.  Also 
told em the anchor rods are 104 ksi yield strength..and came from portland 
bolt...and are 60 inchs long each.... with 6 inch threads
on each end.   Told em that the 18 x leg bolts are
A325 bolts and are 3 inchs long each.    Everything has heavy duty flat
washers and slightly oversized nuts on em.

Their reply was...... snug fit !    This is for my UST  HDX-689 tower.  This
is the old style 689..that weighs 5000 lbs..without the ants and mast, but that
weight includes the bearings  and small  PP  rotor.   The crane operator
weighed the tower when it was unloaded.

What is  ..snug fit ?     Trying to get  answers from UST at times can be
exasperating.
Does anybody even know ?    I was thinking  perhaps  125 ft lbs for the
anchor rods......and 100 ft lbs for the leg bolts.   Leg bolts can always be
replaced...
anchor rods cant.

Tnx...  Jim   VE7RF
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