Bolts for metal control panels

[D]

My thin metal control panel has round head bolts.
The original bolts were used to connect Wico leaf sticks to the panel. Now I have Sanwa sticks.
Question: where can I get round headed bolts (& nuts).
I tried searching at arcadecontrols.com, but no-one really knows.
Maybe somebody know what to search for on google?
Here in the Netherlands, we have nothing here. So I would have to order. Or if someone has about 8 spare ones left I can pay via Paypal.
thanks you

edit: are they called carriage bolts? I'm not sure, but aren't carriage bolts with the square shape below the head to stop the bolts from moving? I'm looking for those difficult to tighten and losen bolts, where you actually have to clamp the thread of the bolt in place while turning the bolt on. I'm sorry for the Engrish.

[OneEyedJack]

You are correct, they are carriage bolts. Should be available at any hardware store.

[dpful]

I've always had a hard time finding ones thin enough to work with arcade stuff.
At the home depot and such, anyways