The length of the slot weld can be obtained from the ratio of

Fusion 360 tab and slot - tab and slot weld Most automotive bumpers, side panels, and fuel tanks are made of polypropylene blends and are best repaired using the nitrogen welding process tab and slot Engineers have found that the current slot and tab design limits the penetration depth of the fillet weld and the plug weld, thereby creating unfused areas

tabletop slot machine tabs that get inserted into small slots that get welded You should probably modify the dxf files with Qcad software and make that slots