> The original Rohn joint bolts were Grade 5, galvanized. That's not
something
> that Lowe's or Home Depot stocks, at least in my experience. They
only carry
> Grade 3 galvanized. Ace will have Grad e5 and Grade 8 hardware, but
it's
> unlikely that it will be galvanized.
Good point, if they are grade 5 you should see two raised lines on the
head of the bolt, hope that makes sense, grade 3 will have no lines on
the top of the head, Grade 8 should have 6 lines on the top of the head
I think.
> The last time I bought genuine Rohn joint bolt kits from Texas Towers
(ten
> years ago, admittedly) they weren't galvanized, adn they were NF
thread.
> Don't know why the change.
I can't imagine any difference between NF and NC, should make no
difference for the installation.
> I would suggest Grade 8 hardware. Somewhat more corrosion resistant
than the
> lesser grades.
I only use galvanized, but then I live near the ocean.
>
> Main thing about the length is that the bolt must be just the right
length so
> that all of the vertical tower load is borne on the non-threaded
portion of
> the bolt (e.g. no threads bearing on the insides of the bolt holes)
but you
> still need to be able to tighten the nut, so make sure you get the
right
> length.
Very good point indeed, don't get shorter bolts.
>
> Remember: do NOT use a hammer to drive the bolts into or out of the
tower
> legs; that will remove the galvanizing from the insides of the bolt
holes,
> making them susceptible to corrosion.
The first Rohn 25 I picked up and put up many years ago was a used tower
and the bottom cross 'rungs' of each section were slightly bent. I
thought that was just sloppy so I carefully straightened them all out
and poured the base. As soon as I went to set the second section I
understood what happened. The small amount of adjustment sometimes
needed between the tower legs was easily accomplished but bending that
cross brace a bit drawing the two legs closer together. Oh well, it was
in fact used.
You might consider greasing the sections where they go together as well.
I've spent hours on the tower with blocks and jacks trying to pry the
sections apart after they have been up for a bit.
Best of luck!
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