John Hawkins wrote:
The ones on my car are Phillips M5 x 0.8. This is based on a thread gauge reading and that the screws fit new Time certs I have of that size.
Thanks John. Are you sure?
I have 4 of these screws, 2 from an original tail light and 2 from a Taiwanian reproduction, and they all fit the threads on both tail lights (but not the one with the screwed-up threads).
The studs that attach the tail light to the car body appear to be the same thread, because the nut that fits these studs also fits the chrome bezel screws.
However, my M5 x 0.8 tap will not thread onto the nut, and it also will not thread into any of the tail light brass inserts that hold the bezel on. So, I concluded that the tap required must have a different pitch.
But I'm not a machinist and I'm probably not thinking clearly.