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Old January 13th 14, 04:41 AM posted to rec.radio.amateur.antenna
Jeff Liebermann[_2_] Jeff Liebermann[_2_] is offline
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Default Low density nuts and bolts used in tower?

On Sun, 12 Jan 2014 20:35:27 -0600, amdx wrote:

On 1/12/2014 7:50 PM, Jeff Liebermann wrote:
On Sun, 12 Jan 2014 18:46:26 -0600, amdx wrote:


I stripped some parts from a large tower at a junkyard.
I saved the nuts and bolts just because I was curious.
The bolts are 5/8" x 1-1/2" long with the marking Kaiser.
The bolts, nuts and even the lock washer are all very light weight.
The lock washer is a slightly different color.
I don't think they are aluminum, I don't think it would have enough
strength. I used a file and gathered some filings and tried to burn
them, they didn't burn so I don't think it is magnesium.
Any idea what metal these bolts might be?
Mikek


Tower hex bolts are usually Grade 5, hot dipped galvanized, medium
carbon steel. For yours, the thread should be in 5/8-11 UNC. No clue
on the typical weight, but I can dig a bolt out of the pile and weigh
it if necessary.


Yes, they are 5/8-11, 1-1/2" long.
I just separately weighed bolts, nuts and washers and then measured the
volume by water displacement. I have 18 of each and used 18 for each
measurement.
Bolts- 530.8 grams/190ml = 2.7934
Nuts - 196.3 grams/68ml = 2.8867
Washers 88.4 grams/32ml = 2.7625

Density of aluminum is 2.70grams/ml
So I guess they are aluminum. Probably have something added, especially
the (split ring) lock washer.


They're aluminum or more likely some aluminum alloy. That's unusual
as the structure would need to also be made from aluminum or it would
corrode. There are aluminum towers, which probably use aluminum
bolts. However, I don't have any experience with them (except on
Field Day, when I wasn't paying attention to the towers).
http://www.alumatower.com

I'm surprised, I didn't think aluminum would have the strength required.
(magnesium density 1.74g/ml)


My guess(tm) is that 5/8" is probably larger than the usual 7/16"
bolts used in small steel towers. The bigger bolt might be strong
enough.

- How many radial spokes are on the bolt head?

None, it just says Kaiser 1-1/2


Aluminum bolts are not rated by Grade 2/5/8 so that's understandable.

OT.
A search showed some Chinese magnesium firestarters don't work.
http://www.youtube.com/watch?v=frDMAOlIGaY


Yep. I bought a Cohgan bar just to see if they were right. Yep. They
don't start easily and don't burn very well. The only one that worked
for me are those from Doan.
http://www.doanfirestarter.com/

They aren't plated, although they have a slightly different hue than
the nuts and bolts.

So, I think they are aluminum.


The lock washers are probably aluminum and probably a different alloy.

--
Jeff Liebermann
150 Felker St #D
http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558