On my Rohn 25, the bolts are just 1-3/4" long and there's no room for a
lock washer. Nor is there a good bearing surface on the round leg for a
lock washer. Using lock washers demands bolts at least 1-7/8" long, a
none standard length, to achieve using all the threads in the nut.
I have seen corrosion next to stainless steel bolts in the galvanize.
Not much, but visible zinc oxide.
Remember that the tower legs put the bolts in tension squeezing the
tower legs and in shear. Shear is greater when the bolt tension is less
and bolt tension is more difficult to achieve with coarse threaded bolts
than fine. Then for the side of the leg that has threads in shear, a
find threaded bolt has a larger cross section, and more threads taking
the shear load from the tubing so is stronger.
73, Jerry, K0CQ
--
Entire content copyright Dr. Gerald N. Johnson, electrical engineer.
Reproduction by permission only.
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