[TowerTalk] Lockwasher Comparison

[Jim Thomson]

Date: Thu, 28 Jul 2016 21:50:03 -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

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

##  Per that chart from Portland bolt  ( same place I bought my 12 x anchor rods from)
you will notice that way less tq is required if the threads are lubricated.... like with 
never seize goop.   Marine grade never seize + nordlocks, whether galvanized or SS
bolts + nuts used, would be the ticket.   Look at G8 bolts...say  .375 size.  Lubricated,
they only require  1/2 the tq  vs no lubricant used.   Ditto with .625 bolts, ( 106 vs 212 ft lbs). 

##  In the end, you are after clamp load.. not tq.   For stuff like the flange plates used on R-65,
you want to mash the surfaces  together, and by lubricating the bolts 1st, then you dont require any where 
near the tq of the same bolt...that’s not lubricated.   I use never seize on lugs on my car..and slightly less tq.
They dont loosen up, yet are easy to remove, when I swap to rain tires in the fall. 

Jim  VE7RF