Welding plates of different thickness - rules of thumb.

[truckdesigner]

Are there any rules of thumb when it comes to fillet welding plates of different thicknesses?

I require the minimum thickness of plate to weld a lifting lug to. The lug is to be 16 mm grade 250 plate. The obvious solution would be to use 16 mm under it as well, but is that necessary, or overkill?


Regards.

 

[gtaw]

AWS D1.1 Structural Welding Code requires a minimum size fillet (or partial penetration groove weld) to ensure here is sufficient heat input to mitigate rapid cooling and resulting undesirable microstructures. The minimum size is based on the thicker of the two members being welded. The minimum size has nothing to do with strength.

If there is a difference in weld size when comparing the size required to transmit the load or the minimum size based on member thickness, the large value is used.


Best regards - Al

 

[Duwe6]

truckdesigner, your question is actually structural. You need to look at the maximum load the lifting lug will experience, and the 'footprint' of that lug onto your structure. Is that small area of your structure strong enough to withstand that load? That loading condition is what will tell you if the area under your lifting lug requires reinforcement or not.