Welded Headed Studs

[jike]

If a contractor decides to fillet weld headed studs to abeam instead of using a stud gun, is that equivalent in strength. I know this depends upon the fillet weld size but I thought I remember hearing something in the past that told me they are not equivalent. I cannot seem to find my reference right now. Can someone help me out?

 

[sundale]

The PCA Design Handbook has a table of E70XX fillet weld sizes that will fully develop a given bar diameter in tension.

A fat doughnut fillet weld seems as strong or stronger than a stud gun's weld to me.

 

[haynewp]

I don't know if they are actually equivalent, but fillet welding appears acceptable as long as it is done in accordance with AWS D1.1 section 7.5 and the stud bases are flat against the base metal as indicated.

 

[JAE]

And test the studs as you would for a stud gun...the bend test on 10% is usually specified.

 

[jike]

Haynewp stated....the stud bases are flat against the base metal...

The headed studs typically have a small setoff on the bottom. Does this need to be ground off before fillet welding?

 

[gtaw]

The small projection is a "flux nugget" on the tip of the carbon steel stud. I believe it is essentially a nugget of aluminum and additional deoxidizers. You can remove it easily or flatten it by hitting it with a hammer. It has never caused me a problem when welding the stud with low hydrogen electrode.

Weld size should be in accordance with AWS as mentioned in one of the other posts.

Best regards - Al

 

[Ron]

Studs are both the electode and the workpiece...no filler.

They can be attached by the typical arc process or with capacitor discharge. They can also be fillet welded. Stuck is stuck as long as you test it like JAE said.

Since studs are mild steel, the welding process (either of them) doesn't screw up the metallurgy.

 

[haynewp]

http://www.aws.org/cgi-bin/mwf/topic_show.pl?pid=27492;hl=fillet stud#pid27492

 

[haynewp]

You could ask someone at AWS or Nelson. If the test for the 10% or whatever AWS requires works, it would be a strong argument if the studs were not flushed down. But since it is working with exception to what D1.1 seems to intend, I am not sure it is completely acceptable.

Say if for some reason they used a smaller fillet for all the studs than what AWS specifies but the test still worked. Would that also be acceptable? Is the intent that if the 10% tested works, that this can be extrapolated to 100% of the studs working on the whole project, or is there some accepted failure number based on the test PLUS the rest of the AWS criteria?