At 07:47 11/9/99 , K9ZM wrote:
>I'm sure that there are many who have done this, but, the manufacturers
>don't supply stainless for the tower leg joints. As inexpensive as a
>bolt
>kit for Rohn 25 is, I can replace them in 20 - 25 years. If yours aren't
>lasting as long as you would like then maybe you need an Engineer to
>assess
>your situation. Stainless frequently requires special handling, i.e.
>Anti-seize and strict torque specs.
================================>
For our tower applications, we're looking at resistance to shearing on
the bolts. The need to achieve perfect torque values is not so
necessary for this sort of application. The specified torque values for
bolting and fasteners will vary according to bolt grade, bolt diameter,
bolt SS material type, use or non-use of anti-seize material.
The use of anti-seize paste is pretty much required in order to prevent
the occasional galling that might occur. (Galling just once teaches you
the lesson to use compound at all times, however)
The bolts in my Rohn 45G are 316 SS with a flat washer on both sides,
plus a spring washer under the nut.
I did not use a torque wrench when I installed them. I just went with
"tight" but not so tight as to stretch a bolt.
I used stainless because it was readily available to me. I tend to
believe that regular "hot dipped" galvanized is just as good for our
tower work in most cases. After fastening the components, a spray of
cold galvanizing stuff from the can will go a long way towards getting
additional assurances to you, especially if the fastener galvanizing
has been applied by some method other than hot dipping.
73,
Bob, N5RP
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