A-pillar bolt thread size?

[The Flying Scot]

Took the mirror brackets off on the A-pillar and they are definitely worse for the wear. So I don't spend all day at the auto store, does anyone know the thread pitch/ size of these bolts.

 

[jjvw]

5/16-18

 

[The Flying Scot]

5/16-18

Many Thanks

 

[Sudo]

Anyone have a source for these? Looking for black button head torx but 1.25 in length instead of stock 1"