if you use it, or intend to use it, as a weapon, then it is illegal to carry. § 2923.12. Carrying concealed weapons. (A) No person shall knowingly carry or have, concealed on his or her person or concealed ready at hand, any deadly weapon or dangerous ordnance. 1974 Committee Comment to H 511 An ordinary pocket knife that is not possessed, carried or used as a weapon is not a "deadly weapon" under RC § 2923.12(A) if a cop asks you why you have it and you say "to slice someone up when they fuck with me" then you are intending it to be a weapon, and that is illegal. if you say "to open boxes at work" then it is a tool and not a weapon. but you know what happens to people who carry knives, right? people who carry knives get shot.