Kirb,
I have never heard of grade 5 stainless bolts, but regardless, the bolts on
a Delhi tower are shouldered or rather the tower is designed to use
shouldered bolts and I am not sure if it is a good idea to stray from the
recommended hardware.
You should be able to verify the proper bolts and if required order the
hardware from MacFarlane Electronics here in Ontario.
www.macfarlaneelectronics.on.ca
I sort of recall Harold has both new and used bolts for those towers. Also
the lock washers on a Delhi are internal star washers, NOT the split ones.
Like all star washers, use only once and replace with new washers if you
replace the hardware.
Ask Harold about the torque specification too, I suspect he will tell you
turn only the bolt, not the nut and tighten until the washer is compressed.
Good luck,
Eric - VE3GSI
-----Original Message-----
From: knesbitt
Sent: May-15-10 7:18 PM
To: Jim Thomson
Cc: towertalk@contesting.com
Subject: Re: [TowerTalk] Taco DMX install instructions (same as Delhi)
I am using 3/4" grade 5 (F593C) stainless bolts on my Delhi HD and
wondered if anyone has a torque spec for these in this application?
Looking at the Taco/Delhi installation sheet I see they have specified a
star type lock washer. I've used the split compression type and am
wondering if they should be replaced? In several instances I can turn
the entire nut/bolt assembly on the leg with the big torque wrench and
in those cases I can see the washer is fully compressed however for some
reason there is a slight gap between the two ends of the washer when
compressed. The ones that are rock solid tight have a nice tight
compression to the lock washer without any gap showing.
Kirb - VE6IV
--
Jim Thomson wrote:
> Date: Sat, 08 May 2010 14:07:22 -0700
> From: Kevin Normoyle <knormoyle@surfnetusa.com>
> Subject: [TowerTalk] Taco DMX install instructions (same as Delhi)
>
> I was curious and found this.
>
> Taco sells the same tower that Wade did as Delhi
> The install instructions for Taco DMX are here
>
>
http://www.tvantenna.com/products/tvreception/mounting/towers/taco/dmx/DMXin
structions.pdf
>
> They show bolts facing in, with a single washer at the nut, (not split
> lock washer, a star lock washer with internal teeth.
> They say "All bolts and nuts are specially heat treated"
>
> ## On Delhi towers... the bolt heads are in the outside.. and
> nuts are on the inside. Same deal with Tryon. On my old LORD
> tower.. 32" wide x 20' straight sections, they used 10 x 3/8" bolts
> to splice each leg, 3 in the flat corner, and 4 on each side. They did
> not stagger the hole pattern, so the nuts have to go on the outside.
>
> ## Trylon staggers the hole pattern... so nuts can go on the inside.
> 2 on one side of V legs is a little higher than the other side. In the
case
> of a Delhi, it makes no difference if nuts are on inside, or outside. If
u put
> the nuts on the outside, you have mote chances of getting stuff like coax,
> rope, etc, etc, hung up on the nuts and any excess threads.
>
>
>
>
> and "These special heat treated bolts have solid shoulders in order to
> prevent the tower sections from shifting. Tighten the nut securely, but
> be careful not to strip the threads".
>
> If the nuts and bolts are heat treated, they must be at least grade 5?
> Doesn't say if galvanized.
>
> ## it doesn't really say anything. Why not jus quote either a SAE G5/8
> spec.. or an ASTM spec.... then you can relate to it. If you can tighten
> up till you strip the threads on a 1/2" bolt.. look out. Any SAE-G5
bolt
> or A-325 bolt uses 94 ft lbs for a galvanized bolt... and 39 ft lbs on a
> 3/8" bolt.
>
> ## I use internal star washers on SS machine screws. We used em also at
work
> on 1/2" bolts [cap screws] for inside iron work. Zero vibration though.
On these traffic
> lights and tall lighting tubes... they all use galvanized split ring
lockwashers....
> OR what appears to be a form of galvanized nylock. The galvanized
nylocks
> used on US Tower corp pulley's don't budge. Trylon uses galvanized
split
> ring lockwashers on all it's lower 5/8" G-5 leg bolts. My trylon was
installed
> back in 1998.. and they are all still tight..checked over the last 2 x
days with the
> new 2' long torque wrench.
>
> ## Apparently, on the latest eia-222 REV G spec... it sez some where
abt the
> only bolt allowed on new tower installs has to be a A-325 bolt... and one
that uses
> a special captivated nut.... that also tells you how much toque has been
applied.
> [torque indicating flat washers] They called em... 'self locking nuts'.
> They also say that if any of the bolts are removed for what ever reason,
the entire bolt,
> nut assy, etc has to be tossed away.. and can't be re-used. If you
look at power co
> transmission towers that were put up yrs ago, they all used either G-5
[G-8 in some places]
> or A-325 bolts and split ring lockwashers. You never see any of those
things falling apart.
>
> ## when I dismantled the 600+ bolts in my old 30" wide L+R tower.. that
was a gov
> install surplus tower... the bolts used had no marking on the heads.. and
99% were rusted.
> I could shear the shanks/threads with just a 1/2" socket wrench... so
they were no more
> than G-2 mild steel. I replaced 600 of em with galvanized G-5 bolts I
purchased from
> L+R. [ all 3x/8"... used for leg splices and also angle bracing.] I
lubricated the galvanized
> bolts.. and quickly found that you could not put 40 ft lbs of torque on
em... maybe 2/3 that.
> What happens if excess torque applied, and galv bolts lubricated
beforehand is this. The nut
> would spin free ! Take the nut off... and it looked like you drilled it
out with a 1/2" drill bit.
> The mating bolt had no threads.. all smooth ! What had happened is the
threads had come off
> the nut and wrapped around the threads of the bolt... and ALL in one
continuous piece.
>
>
> ## did you check the other bolts on your delhi ??? Were any of them
loose ?? You
> may have just missed tightening the pair that fell out. What baffles me
is... the delhi
> uses a 4" overlap on the legs [4.5" on a trylon] with the legs of
the upper section
> on the INSIDE of the lower section. For your tower to fall over.. with
no bolts... the
> bottom of the upper section legs [4" portion] would have to pop right
out..which is
> extremely difficult. One guy here in town 'forgot' to tighten the 2 x
bolts at the 40'
> level of his 48' delhi.. [ one leg only].. and one bolt fell right out.
Both nuts gone..
> and 2nd bolt almost ready to fall out. The top section and F-12 5ba
yagi leaned
> towards the section minus the bolt... not away from it..as yours did.
With NO bolts
> the upper leg should have slid down the top of the section below it...
resulting in
> a bigger overlap of sections.
>
> ## Check your top section out. Several delhi's here in town had loose
rivets in the
> top 4' . I punched em out, then drilled em out to 1/4"...and replaced
with 1/2-20
> G5/8 galvanized bolts. I had 72' of delhi up at my folks place
between 1976-1979.
> Consisted of normal sections 9-8-6, then #5 straights up to the 64'
level.. then I turned the
> #4 section, into a top section, with new thick AL plates, and custom
machined right angle
> tabs in the corners. 2 x thrust bearing used...and Prop pitch sat down
10' down inside the
> tower. 12 x guy wires too.... 4 x per level...and 3 x levels of guys.
The top 16' of tower
> still twisted ! [ 2 x big yagi's on mast] I gave up on delhi's after
that, imo, they are just
> not strong enough. The original 64' delhi was designed for deep fringe
TV ants.. that's it.
> later on, they came out with the #4 + #5 straight sections. BX tower's
in the USA are
> very similar design.. and they now say, no booms longer than 10'... I can
see why.
>
> ## IF they are carefully guyed.. like with a 6 x guy, star of david,
monster cue-rack
> setup, it will be ok.
>
> Later... Jim VE7RF
>
>
>
>
>
> 1/2" diameter x 3/4" bolts on bottom sections. 3/8" x 5/8" for upper
> sections
>
>
>
>
> _______________________________________________
>
>
>
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>
>
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