This is where it becomes odd.
I have a template for hole sizes. I measured it...and bought a nut and bolt in that size. The bolt was too large for the hole and the nut was too small for the stud.
So i bought a bolt one step smaller and a nut one step larger .. all in fine thread.
The bolt will fit but it feels a bit loose and the nut is too big.
Odd, eh ?
Ian.