3 inches and under unless it is not concealed. During Hunting season the size goes up to six inches. But as long as the knife isn't concealed it could be a Katana (NOT ADVISED).
Knives which are illegal to carry include switchblades, butterfly knives, gravity knives, ballistic knives, and non-magnetic knives. belt buckle knives, and "undetectable knives". For definitions of...
The link I provided should help you find an authoritative answer from the State of NC directly, which is the only answer I would trust...
Check out the link to the PDF and note that most of the...
New Jersey - Code of Criminal Justice - 2C:39-3 Prohibited Weapons and Devices... e. Certain weapons. Any person who knowingly has in his possession any gravity knife, switchblade knife, dagger, ...