What diameter is the swing arm bolt, For a Z1?

Before I have to go out and caliper-it- does anyone have the size of this bolt? I need to pick up a drill bit the exact size for my jig, I don't want to have to run home after work- want to go straight over to get the right size bit!

16 mm I believe.

Thanks!

I will be sure and post pics when i get this swing arm done- I am building the first one for "fitment" out of mild steel, to make sure I got is all right and square and what not- and the next one will be Chrome moly.