Iowa pocket knife carrying laws?

Alright so I've been wanting to buy a pocket knife, but I want to make sure it's legal. I understand I cannot carry a blade that's over 5 inches long as a concealed weapon (correct me if I'm wrong). I mainly just want to know if it's legal to carry a switchblade or spring assisted knife. Example: Spring Assisted stiletto w/ breaker. I've heard spring assisteds are legal almost everywhere, I want to only carry it for self defense purposes if ever anything happens in which case I would need it. I already carry a small lock blade pocket knife, that you pull the blade out of the handle. I know this IS legal, the blade itself is a mere 2 1/2 inches long. I've had it for many years and it sticks. Don't give me the long form of the Iowa laws, I've read it many times. Not fully comprehending it though.