Many of those city ordinances are listed in this thread:
http://www.okshooters.com/showthread.php?1824-knife-question
You have to search for a lot of the ordinances, but here's a quote from Crosstimbers Okie who did a lot of research on it:
"Oklahoma state law prohibits nothing based on blade length. There are three municipalities that I'm aware of that limit knives by blade length. They are: Muskogee, six inches (13-421 & 13-422) and Norman, four inches (15-504) . In Oklahoma City there's an ordinance against offering for sale or exhibit pocketknives with blades greater than four inches (30-311 & 30-302). Look out Walmart!"
http://www.okshooters.com/showthread.php?1824-knife-question
You have to search for a lot of the ordinances, but here's a quote from Crosstimbers Okie who did a lot of research on it:
"Oklahoma state law prohibits nothing based on blade length. There are three municipalities that I'm aware of that limit knives by blade length. They are: Muskogee, six inches (13-421 & 13-422) and Norman, four inches (15-504) . In Oklahoma City there's an ordinance against offering for sale or exhibit pocketknives with blades greater than four inches (30-311 & 30-302). Look out Walmart!"