I am a detective in Northwest Ohio with a police department. Your replies seem to be right on the money. There is no clear law per the state on length. Your best bet is to be upfront about having it on your person and state that you use it for some type of tool usage. Never pull it out and never try to hide it as youre being approached. Just be up front and honest and it will get you a long ways when it comes to this particular statute and remember all of these deal with concealed carry not open carry. I am more too happy to field any questions on Ohio laws and if I dont know the answer I will research and find one.
what about school? some kids carry them not for anything in particular but just in case there's a situation in which they'd be very helpful