Drag brakes/tandems/singlespeed/thread pitch anyone?

Can anyone tell me what the thread pitch is to fit an arai drag brake to a tandem? would it be the same pitch as a screw on freewheel?

and if so would it be possible to mount a singlespeed freewheel on the other side of a respaced tandem hub to have a sort of singlespeed/cassette flip flop hub? (albeit with a silly chainline)

Thinking about it to fit to a touring bike, having a last-ditch singlespeed freewheel incase gears on the cassette get mashed.

tell me i’m doing it wrong

It’s ok, i found my answer. was on wikipedia all along.