Not sure what Rohn provides. My tower was a used AM BCB tower, a couple
of 10' sections were welded together after bolting. A BC engineer told
me this is common practice to increase conductivity. I do have some
stamped steel dished "kinda look like lockwashers" that came with the
guy anchors I bought from Rohn. They look pretty MM so I used Nordlocks
on the custom shaped U-bolts that go around the tower legs and bracing
at the same time. Just had a complete inspection after one year,
everything was tight.
Standard practice is to put the leg bolts in nut up, so when it falls on
the ground you see the nut is missing or that the bolt isn't there. Or
worse w/o your hard hat if it is a 5/8 x 2". If you can apply the rated
torque of 90 to 120 ft-lbs for waxed + galvanized bolts they might not
need locking washers, but the Nordlock insurance is pretty cheap
compared to everything else. A plain A325 5/8 needs 220 ft-lbs.
http://www.portlandbolt.com/technical/bolt-torque-chart/
Several articles I've read other than the Nordlock video/data seem to
agree that split ring washers are about useless.
I've never seen hot dip galvanized internal or external tooth
lockwashers. I use machine screw sizes internal ones, mostly on K-nuts
(KEPS) for electronics.
Grant KZ1W
On 7/28/2016 20:09 PM, Jim Thomson wrote:
Date: Wed, 27 Jul 2016 19:15:38 -0700
From: Grant Saviers <grants2@pacbell.net>
To: Jim Thomson <jim.thom@telus.net>, towertalk@contesting.com
Subject: Re: [TowerTalk] Lockwasher Comparison
Surfaces need to be clean, the opposite of what is desirable for
structural fasteners that should be lubricated. A325 5/8" hot dip
galvanized structural bolts I've bought for Rohn 65 tower leg flanges
have had a blue wax coating. So they are "1 for 3" (no O2 is ok, no
exposed Fe not ok, not clean not ok) re using Loctite. Hence these bolts
got NordLocks. Thru leg bolts in shear such as R25/45 don't have the
axial stress cycling of flange leg towers, so most any nut that doesn't
fall off is fine.
Grant KZ1W
##Ok, so what does Rohn supply for nuts, bolts, flat washers and lockwashers,
on their 25/45/55/65 towers ??
## a buddy with 55G... has had one of the leg bolts fall right out, and ended
up at base
of the tower ! That was at the junction of the top 2 x sections.
## Internal tooth and external tooth lock washers usually work pretty
reliable.
Jim VE7RF
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