Most states are not 4 or less. The 50 states are all over the map as to regulations. The state I live in has no limit, but you cant carry concealed weapons. A knife is not considered a weapon, unless it was your intent to use it as a weapon. So if mr. cop asks whats this for, and you say, protection, your busted same as carrying an illegal firearm concealed. You say opening boxes and cutting my apples as well as general utility, and you go on your merry way. Then towns, counties and cities can enact ordinances that further restrict things too. So you cant just go by state law.