Fatigue strength of fillet-weld, plug-weld, and slot-weld joints

Most common joints are made up of fillet weld or the butt weld Plug and slot welds are not generally used in structural steel work Fig

We start with the basics, explaining what plug and slot welds are and why they are used in

plug and slot weld To enable thicker plate to be joined by 'spot welding' a circular or elongated hole may be machined through the top plate, enabling either a plug or a slot weld

plug weld 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