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Old January 13th 14, 02:35 AM posted to rec.radio.amateur.antenna
amdx[_3_] amdx[_3_] is offline
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First recorded activity by RadioBanter: Aug 2013
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Default Low density nuts and bolts used in tower?

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


- How many radial spokes are on the bolt head?

None, it just says Kaiser 1-1/2


http://www.boltdepot.com/fastener-information/materials-and-grades/bolt-grade-chart.aspx
- Is the bolt magnetic or non-magnetic?


non-magnetic

- You need to get magnesium up to 430C in order for it to start
burning. It will then go to about 3000C.


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




- The actual weight of a bolt would be helpful.


530grams/18 = 29.48 grams each bolt.

- Lock washers can be hot dipped galvanized, but are usually just
flash plated with zinc. That's because the thick layer of
zinc can be scraped off as the nut is tightened.


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

So, I think they are aluminum.

Salvaged these at least 5 years ago, cleaning out my shed and ran across
them today. I decided it was time to check them out.
Mikek