[TowerTalk] My 48' Delhi Self Supporter folded over :-( lost itsbolts!

[jimlux]

Gary "Joe" Mayfield wrote:
> What are folks' opinions on nuts with nylon inserts in the cap?  We
> refurbished a Jontz tower, and used them.  They seem to be doing very well
> after 5 years.
> 

That's a special case of the general "deformable threads" kind of 
fastener. They work just fine, however, for critical applications, there 
will be a "running torque" spec that you have to meet when installing 
them. That's the torque while the nut is actually moving, as opposed to 
the usual "spin the nut on until finger tight, then put the wrench on 
and pull til it hits the number" technique.

In a tower application, holding sections together, I would think that 
you're loading the bolt only in shear, so how "tight" the bolt is isn't 
all that big a deal.  A pin and cotter key would probably work almost as 
well.  As would a jam nut.  Basically anything to keep the bolt from 
falling out.

It's not an application like a rod bolt on an engine or a wheel stud/lug 
nut, where there are signficant loads in tension from the application.

(The bolt at the bottom of the base of a self supporter keeping it from 
falling over are another story.. they ARE loaded in tension)