What are the Pennsylvania knife carrying laws?

There is not a legal age in which a person can carry a traditional pocketknife. The law states the act of carrying an "open bladed cutting instrument or a knife which opens by spring, lever, or any such devise (switchblade) shall be considered a misdemeanor. In addition, knives of any type cannot be taken onto school property. Such action is considered a criminal misdemeanor and also results in mandatory expelling of a student enrolled in any Pennsylvania public school.