INTELLIGENT WORK FORUMS
FOR ENGINEERING PROFESSIONALS

Log In

Come Join Us!

Are you an
Engineering professional?
Join Eng-Tips Forums!
  • Talk With Other Members
  • Be Notified Of Responses
    To Your Posts
  • Keyword Search
  • One-Click Access To Your
    Favorite Forums
  • Automated Signatures
    On Your Posts
  • Best Of All, It's Free!

*Eng-Tips's functionality depends on members receiving e-mail. By joining you are opting in to receive e-mail.

Posting Guidelines

Promoting, selling, recruiting, coursework and thesis posting is forbidden.

Jobs

Tack welding A108 gr.1045 rod

Tack welding A108 gr.1045 rod

(OP)
Hi All,
I am inspecting a project where the jurisdiction has instructed the contractor to tack weld threaded A108 gr.1045 rod to fastening nuts for the purpose of fouling the thread. The rod material isn't pre qualified per AWS D1.1. I suspect that there is a reason for this. Can anyone tell me the downside of tack welding to this material without pre or post heat. By the way these rods are being used as hangers for heavy utilities.
Thanks for your time,

RE: Tack welding A108 gr.1045 rod

IF the tack-weld is outboard of the nut, and is predominately [or wholly] on the threaded rod, no problem exists; it just 'boogers' the threads and keeps the nut from loosening.
On the other hand, if that weld is in an area that is carrying a load, the contractor has now degraded, and thus ruined, a load-bearing member. Contractor now has to calculate the new, lower, strength of the assembly, and get this value approved by the design engineer.

RE: Tack welding A108 gr.1045 rod

My first question is why is the jurisdiction giving directions to the contractor?

To answer your question, the concern with tack welding is that it can create local stress raisers due to the localized heating and cooling effect. The heating and cooling causes expansion and contraction over a very small area and the weld heat can change the material properties of the steel. That said, tack welding a nut to an anchor rod is done quite frequently and I am not aware of any failure that has been attributed to such a practice.

RE: Tack welding A108 gr.1045 rod

Quibble:
"The heating and cooling causes expansion and contraction over a very small area and the weld heat can change HAS changed the material properties of the steel."

RE: Tack welding A108 gr.1045 rod

(OP)
Thanks for your responses. I am aware that this is a common practice but that being said... It doesn't necessarily make it a sound practice. In other settings such as OSHPD or DSA I have seen entire systems rejected and replaced for the same reasons. I should have mentioned that a qualified WPS is not on file for this application and my concern was for the carbon content of this material and the lack of preheat potentially causing a crack.
Thanks

RE: Tack welding A108 gr.1045 rod

Some millwrights refer to welding nuts and bolts to prevent loosening as "killing" them.

I agree.

Red Flag This Post

Please let us know here why this post is inappropriate. Reasons such as off-topic, duplicates, flames, illegal, vulgar, or students posting their homework.

Red Flag Submitted

Thank you for helping keep Eng-Tips Forums free from inappropriate posts.
The Eng-Tips staff will check this out and take appropriate action.

Reply To This Thread

Posting in the Eng-Tips forums is a member-only feature.

Click Here to join Eng-Tips and talk with other members!


Resources


Close Box

Join Eng-Tips® Today!

Join your peers on the Internet's largest technical engineering professional community.
It's easy to join and it's free.

Here's Why Members Love Eng-Tips Forums:

Register now while it's still free!

Already a member? Close this window and log in.

Join Us             Close