Adding a Stick Tapped Bolt Hole

Can I tap a 5/16th or 3/8 th inch bolt (one) hole in the side of my dipper stick for a quick disconnect bracket for my thumb? Or would I need to tap the hole in a piece of metal plate and weld the plate on? If so, what shape of plate? Weld it with what type of wire? There are no doublers in the area I want to do this. This bracket will also be attached to a line clamp on top of the stick.
hugs, Brandi

Adding a Stick Tapped Bolt Hole