[TowerTalk] Yagis and Rivets

[Bill Coleman AA4LR]

On 3/16/00 3:27 PM, Andrew Williamson at andrew@gi0nwg.freeserve.co.uk 
wrote:

>It's interesting to note that Force12 are now using bolts to mount the
>element brackets to the boom in their higher rated antennas.  It makes
>you wonder about the rivets!

One must also wonder about the installation practices. I've heard others 
on TowerTalk speak of drilling a hole, putting the rivet in, and then 
pulling it.

In aviation, when rivets are used, one must be careful to deburr all 
surfaces (as best as one can). These small bits of aluminum can prevent a 
fastener from seating properly, and produce stress risers which can crack 
the aluminum, or work loose with vibration and cause the fastener to 
become loose. 

Properly used and installed, rivets (even the blind variety) can be quite 
strong. Bolts are often better advised in high stress areas -- one reason 
being that they are steel and offer more strength than aluminum rivets. 
This may be the reason F12 has moved to bolts in their element brackets.



Bill Coleman, AA4LR, PP-ASEL        Mail: aa4lr@radio.org
Quote: "Boot, you transistorized tormentor! Boot!"
            -- Archibald Asparagus, VeggieTales


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