Welding of standard nuts

[trainguy]

Hello all.

Does anyone have any objections to using standard 3/4 inch dia. nuts as weldnuts?

tg

 

[metengr]

Standard as in size or carbon steel material?

 

[KENAT]

Yeah, round here the 'standard' nuts are stainless.

Define what you mean by 'standard' then someone may be able to help.

KENAT, probably the least qualified checker you'll ever meet...

 

[trainguy]

Guys,

I meant standard size and carbon steel, e.g Gr 5.

tg

 

[MintJulep]

It may or may not be alright, depending on the details and application.

I have seen it done such that the nut was not firmly in contact with whatever it was welded to. The welds failed, preload was instantly lost, and the joint failed.

I've seen it done with smaller nuts on thin sheet - resulting in deformation of the sheet. This essentially built a spring into to the joint since the preload did not fully squish the deformed sheet.

 

[GRoberts]

I would never recommend welding a nut or bolt not intended to be welded. The chemical analysis and mechanical properties of a nut intended to be welded vs ones that aren't are entirely different. The nuts not intended to be welded will form hard/brittle welds, and the HAZ of the weld will significantly soften the nut material. Nuts intended to be welded are made from weldable material and aren't intended to be high-strength.