I don’t know any official specific document that restricts welding or grade 8.8 fasteners however I never welded high strength fasteners for the reasons this website gives:-
Abdullah J,
Just Google and you will see it is definitely not recommended.
However, you are looking for specific reference.
I do believe there is one x code /standard that does prohibit it (I had a big issue with this on a previous project)but cannot remember which.
I found via Google so you can do the same.
If all else fails you can quote MintJulep as your reference !
In most welding codes there are rules about welding on high strength materials, especially if they are heat treated.
These welds would need procedures and qualifications like any others.
And that is why people generally do not weld high strength fasteners.
And of course, MintJ is correct.
I find it extremely unlikely that a grade[ ]8.8 bolt has not been heat treated. The heat treat and your grade[ ]8.8 rating will not survive welding.
1. AS/NZS 5131 Structural steelwork - Fabrication and erection:
Welding of materials of property class 8.8 and above shall not be permitted. Welding of nuts shall not be permitted unless they are specifically selected as a weldable product.
2. Specification of threaded bar in structural applications:
High tensile threaded bars should not be heated beyond the transition temperature (in the order of 500°C)
as it would reduce its strength due to annealing. Therefore welding should be totally avoided on high tensile
threaded bars unless they are reheat-treated after welding.
Some practitioners weld hardened nuts in certain applications. This practice should be avoided as
the material properties of a hardened nut would alter if the nut is heated beyond the transition
temperature of the material which is in the order of 520⁰C.
