Plug weld onto edge

[trainguy]

All,

We are designing a tee joint between 2 steel plates 0.25 thick. There is no clearance for usual double sided fillet welds. We are looking at making a slot in the top part, extending the stem slightly upwards into the slot and filling up the slot with weld metal.

Is this done? How to reconcile fatigue behaviour vs the usual fillet welds?

tg

 

[racookpe1978]

There will be a significant reduction in strength anyway. You're comparing two full-length (1/4 inch right?) fillets balanced on both walls of the tee against a single "row" of intermittent (thus the total weld length is much, much shorter!) slot welds.

Further, each slot weld is at maximum only 1/4 across (at maximum!) - and the single slot weld can not resist twisting (vibration or fatigue) forces as well since it has 1/6 the working distance between the centerline and the resisting force. (1/8 inch maximum lever arm, compared to 2 weld edges at 1/8+1/4 inch lever arm.)

 

[trainguy]

OK - I've made a change.

I'll add welding at the underside as well to get back to something similar to 2 - 3/16 fillets. The weld I am replacing was only 2.5 inches long and the slot we are using already exceeds that length.

Thanks.

tg