[TowerTalk] Proper torque settings for G-2800 rotator mast clamp bolts?

[Grant Saviers]

I believe from using 3 Yaesu rotators, the 2800 bolt torque limit is 
more about the yield strength of the die cast clamps than the bolt 
strength.  A torque wrench will measure what "1/2 to 1 turn" really means.

The bolt heads will be marked so that will reveal the bolt strength and 
the permitted maximum torque can be looked up.  Since everything yields 
a bit, it is best to tighten in a pattern and repeat it 3 times.  After 
a day or two is even better but that is another tower climb.

Grant KZ1W

On 12/24/2022 11:50, Alan Higbie wrote:
> As the result of an extremely high wind event, I will soon be going up the tower to loosen the G-2800 mast clamps, realign the mast and then re-tighten the M8 x 70 bolts.
> 
> The Yaesu G-2800 manual says:
> 
> “Caution: Do not over-tighten the nuts on the mast clamps.
> They should be tightened until the spring washer becomes flat, then tightened further by 1/2 to one turn maximum.”
> 
> I am still using the original hardware supplied with the G-2800.
> 
> These spring washers have been in service for 5 years - so their springy-ness may not be the best indicator for torque.
> 
> I believe that torque settings depend upon the grade of hardware being used: e.g. 8.8, 9.8, 10.9 or 12.9 - but I don’t know the grade of the stock hardware.
> 
> What its the proper torque setting for these M8 x 70 bolts?
> 
> 73,
> 
> ~ Alan Higbie K0AV
> 
>    
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