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.
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 would suggest Grade 8 hardware. Somewhat more corrosion resistant than the
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.
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.
NC = National Coarse; NF = National Fine.
Mahlon - K4OQ
> From: "Julio Peralta" <email@example.com>
> Date: 2004/02/05 Thu PM 01:03:18 EST
> To: <TOWERTALK@contesting.com>
> Subject: [TowerTalk] rohn 45 leg bolts
> The Tampa Amateur Radio Club is getting ready to erect a R-45 tower. We need
> 8 sets of leg bolts. Rohn specs call for 3 each, 5/16" X 2 3/8" NC bolts and
> 3 each, 7/16 X 2 1/4" NC bolts per section.
> Does any one have any spares on hand?
> What does the NC in the spec stand for?
> I would guess that any commercial fastener vendor would have suitable bolts.
> BTW we also need a rotor shelf for the R-45 to complete the install.
> Julio, W4HY
> See: http://www.mscomputer.com for "Self Supporting Towers", "Wireless
> Weather Stations", and lot's more. Call Toll Free, 1-800-333-9041 with any
> questions and ask for Sherman, W2FLA.
> TowerTalk mailing list
See: http://www.mscomputer.com for "Self Supporting Towers", "Wireless Weather
Stations", and lot's more. Call Toll Free, 1-800-333-9041 with any questions
and ask for Sherman, W2FLA.
TowerTalk mailing list