“If anyone wants to be serious about this, the formula for the pull-out
resistance of lag screws is on page 8-10 of this document
<http://www.fpl.fs.fed.us/documnts/fplgtr/fplgtr190/chapter_08.pdf>.
Compare whatever numbers you get to the ultimate strength of 3/16 EHS
guy wire, factor in an appropriate safety factor, and I bet you'll
abandon the idea. “
I read it and I see that even in pine, living or at least not rotting, a thread
penetration of 12X shank diameter will break a lag in tension.
Pretty amazing, really! So a half inch lag should be more than enough for 3/16
wire. But why depend upon pure tension when you can use a loop and depend only
upon the stump?
That said, the through bolt and big washer “looks” a lot better and doesn’t
depend much on wood quality.
I don’t advocate using rotting stumps, but if one needs a temporary solution a
pine stump is fine for several years, all the more so if you use a loop around
it to anchor the wire. No, I’ve never done it, BUT I regularly butt 6-8”
stumps as hard as I dare with my 50HP tractor and it has no effect except to
shake me up and scratch the stump a little. Generally, they can’t be uprooted
by that method, but will eventually break off after most of the wood has gone
punky. I think most of them retain lots of strength for at least five years,
maybe longer. No doubt there is some variation among the species, Some retain
a strong heart much longer than others.
WL
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