On Thu, 10 Jun 2004 13:17:05 -0400, Jeff Wisnia
wrote:

all of these answers assume that the threaded thing will never need to
be *un*screwed. after sitting for a while, a thread will likely take
more torque to remove than it took to screw it in in the first place.
if the predominance of right handed persons and the greater hand
strength available to turn clockwise were the reason wouldn't left
hand threads be better?

It would be interesting to find out what percentage of all installed
threaded fasteners are ever again deliberately loosened.

I'd but my money on it being less than 1% of them. And, considering that
probably more that 95% of fasteners are currently being tightened by
machines and not hands, in our mass production world, your argument is
reasonable, but probably moot.

Jeff


In today's world, sure, but the thread started out asking the origin
of the rotational bias. a better question would be what percentage of
threaded fasteners at the time (whenever that was... ; ^....) were
removed. I bet it was pretty high. there would have been little reason
to use an expensive threaded fastener otherwise, when nails and rivets
were were cheap and easy.