thule hitch rack locking pin thread size?

[AngryScientist]

good morning paceline.

i've got an upcoming trip that i need to carry a few pals bikes. they are all from the city, so none of them have cars of course. my nice bike will ride happily on the roof, but theirs will ride on this thing that i just got for cheap money off of ebay.

a quick search shows that thule's locking hitch pin is, the snug tite, is sixty bucks! that's more than i paid for the rack, and of course, will not be doing that! the rack didnt come with a threaded bolt or anything, so before i head to Home Depot tonight, anyone know what size thread the anti sway bolt is ? metric probably right?