[TenTec] rohn 25

[Roger Borowski]

I've been using Stainless Steel bolts and nuts on my towers and antennas for
over 40 years and have not experienced any corrosion as 304 grade Stainless
Steel, which is commonly used for hardware, is inert from rust or corrosion
with other metals, unlike brass and copper against steel and/or zinc and
aluminum. It must be lubricated with never seize, which also protects the
Stainless Steel from friction galling against another Stainless Steel
fastener. As far as brittleness, Grade 5 steel bolts are relatively soft in
comparison to Grade 8 in steel bolts, although grade 8 will withstand far
more tensile stress. 304 Stainless Steel falls somewhere between grade 6 and
7, actually closer to 6, so its stronger than grade 5 steel but just a bit
more brittle. Not a problem in tower leg fastening applications as if the
hardware is amply tightened, there will not be any impact or shear pressures
on the bolt/s. Sorry for the off-topic postings. Just trying to set the
record straight as tower safety and susceptibility to corrosion is not to be
taken lightly.
73, Rog-K9RB  (former metallurgical engineer) (But not a Doctor!)

----- Original Message ----- 
From: "Dr. Gerald N. Johnson, electrical engineer" <geraldj at isunet.net>
To: "Roger Borowski" <K9RB at arrl.net>; <tentec at contesting.com>
Sent: Saturday, October 18, 2003 3:01 PM
Subject: Re: [TenTec] rohn 25


> There's no room for lock washers on my Rohn 25 with 1-3/4" bolts that
> are there. The bolt ends are flush with the tops of the nuts. Fine
> thread probably doesn't need lock washers because of the spring of the
> tube. There is a great deal of survival difference between hot dipped
> galvanized and electro plated zinc. Same material but so much more for
> hot dipped than for plated. There will be more corrosion next to the
> stainless steel than next to the galvanized hardware, though these days
> the stainless may be easier to acquire. Stainless may have a higher
> strength, but what about impact strength? Grade 8 steel is stronger than
> grade 5 still but is more prone to fracture from impact.
>
> 73, Jerry, K0CQ
>
> -- 
> Entire content copyright Dr. Gerald N. Johnson, electrical engineer.
> Reproduction by permission only.
>