I have quite a few straight sections of tubular tower (made by an
obscure manufacturer who has long been out of business) that
I want to put up this year as a guyed tower. I am lacking the
bolts for the joints.
I am interested in using galvanized hardware, as Rohn does, because
it doesn't require lockwashers and seems in general to be pretty
impervious to vibration.
I have two, related questions for this group.
First, does anyone have any favorite sources for galvanized
hardware?
Specifically what I need are 0.5 x 2.5 inch bolts, any thread
pattern.
I know about Rohn and McMaster-Carr. Others?
My second question has to do with the necessary strength of the
bolts.
The tower will be 160', guyed four times. The legs are similar to 2
inch
schedule 40 water pipe, and the tower has a 24 inch face. There are
two bolts per leg, like Rohn 45, with each section being 10 feet
long.
The tower terminates with a oversized sleeve that slips over the
section below, just like Rohn 45-ish tower.
McMaster-Carr does have grade 2 galvanized bolts in their catalog.
Tensile strength is listed as 74,000 psi.
I realize that this is not ideal, and that something like grade 5
would
be better. But the half inch bolt is also quite a bit bigger than
most
other tower joint bolts I see.
Can I get the grade 2 bolts, or should I keep looking? I assume
that
the only concern is having the bolts shear. Compression failure
doesn't seem like a problem, given the joint overlap.
- Pat
N9RV
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