Thread size on a standard 'A' bar

[dave.j.robbo]

Might be an odd question, but on my standard Toyota A bar, there are some captive nuts in the top hoop, but I can't seem to get bolts to fit them. Thought they were 6mm, but no... Unless they're just crudded up with crud!!

Didn't want to run a 6mm tap in them just in case they were a special toyota only size!

Any ideas??

[NiftyNev]

I have four (two each side) on the underside of mine and they are 6mm.Spray a little WD40 in them and gently try the 6mm tap and keep backing off to clear the tap.

Neville