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Re: Rolled Threads

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Thanks for the information 

With regards to the recommendations to allow rolled threads, that is not an
option since the agency that checks California public schools has ruled
that rolled threads are not acceptable.  Thus on school jobs we have to
follow the  rules.

As I under it, the only provision that limits the shank diameter of an A307
bolt is ANSI B1.1 which defines thread geometry. 

It seems that the use of rolled threads would cause several problems if the
bolts were used to transfer shear forces in steel connections.  The smaller
shank would result in a reduction in the shear capadity of the bolt.  But
given the fact that most engineers use the values in the steel manual it is
possible that some connections would be "overstressed" if rolled threads
were used without the knowledge of the engineer.  You might argue that
there would be no real problem, and I might agree, but there are some
"experts" out there who note the  technical code violation..

Secondly because the diameter of the shank is less than the diameter of the
threads, the use of a standard size hole would create a situation where the
difference in diameter between the  diameter of the hole and the diameter
of the bolt would be greater than 1/16" and thus be at odds with the code. 

Christopher you are right that the engineer needs to be familiar with the
standards referenced.  I wonder how many structural engineers have read all
of the standards referenced from the standards referenced in their
specifications?  How many offices have a copy of ANSI B1.1, which I believe
costs in excess of $140.00?  By the way I am one of the old farts in my
office and am usually the one suggesting that engineers read standards.

I did visit the engineering library at UC Berkeley, and they did not have a
copy of ANSI B1.1 or B18.2 and I could not find the necessary information
in other references.

If your point is that I may not have lived up to an ideal espoused by some,
you may be right.  But if that level of perfection is required I would
suggest that not one structural engineer in a thousand currently fulfills
this ideal

Mark Gilligan


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