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Re: Welding and galvinizing of A449 Threaded Rods

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A449 is a heat-treated rod material (materially, it's the rod equivalent 
of that for A325 bolts). I think there is a concern that the heat input 
of the weld can reduce the strength of the rod by relieving the effect of 
the heat treatment. I'm not sure how extensive the zone of damage would 
be, but the question comes down to if it is large enough to affect the 
stripping strength of the threads that are engaged with the nut, or the 
strength of the rod at the critical plane (just inside the bearing face 
of the nut). I'd be most concerned if the tack weld were placed on the 
bearing face of the nut (i.e., at the critical plane), but that is not 
the usual practice.

Unfortunately, I don't know of a specification or testing report that 
addresses this issue.


Brad Friederichs wrote:
> I am using some 2" dia by 48" long threaded rods to attach the base plate of
> a sign standard to a drilled pier footing.
> The rods were supposed to be A307 but the contractor used A449.
> At the bottom of the threaded rod is a nut that is tack welded to the rod.
> In addition, the rods are galvanized.
> The bolts have very low stress, about 5-7ksi in tension under working loads.
> Do you know what specification or testing report I can quote that will show
> that these bolts are ok or do they have to be replaced?
> Thank you,
> Brad Friederichs