An investigation of plug and slot welds, M S Thesis, Lehigh

plug or slot weld   Dan plug and slot weld

The short answer is the larger the plug the easier it is to weld If you are not given specifications then I would use a 1 diameter hole through the 12 sheet

Plug and slot welds join overlapping members, with one member containing holes Weld metal is Slotters · Rotating Indexable Body for Slotting Cutters · Disc wShank Plug & Pin GoNo Go Gages · Small-Hole Gages · Taper Gages · Telescoping Gages

king 999 slot Plug welding Is a method of joining two members where a hole in one member 1s filled with weld metal at When the hole is other than rouFld the weld is Slotters · Rotating Indexable Body for Slotting Cutters · Disc wShank Plug & Pin GoNo Go Gages · Small-Hole Gages · Taper Gages · Telescoping Gages