Need a book? Engineering books recommendations...

Return to index: [Subject] [Thread] [Date] [Author]

Re: Welding and galvinizing of A449 Threaded Rods

[Subject Prev][Subject Next][Thread Prev][Thread Next]
Brad, you have a couple of issues to address.

1) A449 is a Bolt or Stud spec, however C1040 or C4140 material is used and quenched and tempered to the 449 requirements. You need to find out if the rods meet the type 1 or type 2 chemistry. If you have type 1 it is ok to hot dip the rods, if type 2 they would have to be mechanically coated.

2) How big of a "tack" did the contractor use. I have seen some big tacks in the field. The problem is how much heat was input into the steel. With quench and tempered steel, welding will cause a change in grain structure and may cause a heat effected zone that could lead to a fracture. If the contractor has welded the nuts on and you need them to resist uplift , replace the rods. On the other hand, if these are little tacks and you have low stresses and the rods are in place, it may be best to leave them.

3) If the rods are not in the concrete and there are not a large number of them, I would reject them on the basis of ruining the tempering. This will cost the contractor some money, but it may also wise him up about welding on anchor bolts that may have to have the properties of the 449.

PS, I have seen rods in this same situation left in place and rejected depending on the mood of the EOR. Good Luck

Steven Powell, P.E.