What size holes to drill in keggle for 1/2" couplings??

I am sure this is somewhere on this forum but searched & searched and couldn't find it.

I am welding some 1/2" half couplings to my kegs to start assembling my brew rig. I have drilled 7/8" holes for the couplings. This will allow them to be welded to the outside of the keg.

Is this the right way to set this up, or should I drill holes that will allow the half couplings to sit halfway through the wall of the keg?

Use a 7/8" step bit, but only drill out 13/16"

You really want the coupling to insert into the hole rather than face-welding them. There's a good chance the interior threads would become unusable. It's best to not drill the hole until you have the coupling in your hands. The OD varies wildly between 1" and 1.25".