What is the size of the threading for the Antenna studs?

[wct69]

Not getting  a response off the general tech board, so I thought I'd ask the local knowledge base.
I have a 2000 IS with both whips, radio and CB.
I want smaller antenna.  I will likely go with Firestix .
What I don't know and cannot seem to find reference too is the
size of the threaded studs that the stock antenna whips mount onto.
While I realize that this will cost me points on my man card,  I will ask any way.
What is it exactly that I need to know to order these correctly?
I think it is likely:
Thread size
Pitch ( I think that is the distance between the threads????)
The length of the threaded stud

So,  I need both the information and whether or not I have the necessary information and terminology down.

Any advise in clearing up this glaring point of ignorance on my part would be greatly appreciated.
Chris

[Thunderbolt]

Sorry I couldn't help you.  I went out and unscrewed the radio antenna on the Interstate and attempted to find some bolt that I had taken off the bike somewhere that looked the same but could not find one.  I also looked at the manual and could not find the particulars on it.  If you take it off the bike and take it to a hardware store sometimes they will have a display where you can screw bolts into a nut or nuts onto a bolt to determine if they fit and get the information there.

[wct69]

Thanks for the effort Thunderbolt.
Judging from the chorus of crickets chirping on this one, this subject has not gotten much play.