Is the washer removable or permanently attached to the junior adapter as a single piece (and only the wing nut is removable)?
Is this the best adapter to mount a standard 3/8" photo head to the top of a compatible light stand?
This device appears to be used for making impromptu light mounts in sheet metal or masonite paneling. The stud looks like a standard 5/8ths dia. It sounds like you are looking for a 3/8th in mount. Those are not very common. I recently purchased an adapter that fits over a 5/8th stud. try searching for 3/8th to 5/8th stud adapter. some inexpensive light stands are 3/8ths.