[TowerTalk] Lockwasher Comparison

[Grant Saviers]

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 at pacbell.net>
> To: Jim Thomson <jim.thom at telus.net>, towertalk at 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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