Kansas - Article 42. Crimes Against the Public Safety; Weapons Control. Section 21-4201. Criminal use of weapons is knowingly... (1) Selling, manufacturing, purchasing, possessing, or carrying any... knife commonly referred to as a switchblade knife, which has a blade that opens automatically by hand pressure applied to a button, spring, or other device in the handle of the knife, or any knife having a blade that opens or falls or is ejected into position by the force of gravity or by an outward, downward or centrifugal thrust or movement... (2) carrying concealed on one's person, or possessing the same with intent to use unlawfully against another, a dagger, dirk... dangerous knife, straight-edged razor, stiletto, or any other dangerous or deadly weapon or instrument of like character, except that an ordinary pocket knife with no blade more than four inches in length shall not be construed to be a dangerous knife, or a dangerous or deadly weapon or instrument... Kansas Case Law: - "[city] Ordinance more restrictive than 21-4201 upheld." http://www.knife-expert.com