If you read the code, there's nothing in it about length or fixed vs folder...at the state level. The problem comes from the local cities. For example, Akron has a length limit and I've learned that fixed are frowned upon, being seen as weapons...which is what you are trying to avoid.
I found a lot of good info scouring the concealed carry sites. CCW in Google should get you those.
Oh, and here's something to remember, just because you know the law doesn't mean that the office arresting you does. Ohio laws are very vague, and you might get arrested just so that the district attorney can sort it all out...or your own lawyer at your own expense. It is risky to carry what a lot of people call a weapon. (I had an LE say that nobody anywhere except LEs should carry any blade longer than 2 inches...in AMERICA!!)
Enjoy your hobby, but keep your nose clean...that's what I do.
(Not a lawyer, and don't claim to be giving legal advice...blah, blah, blah)