It's summer time, schools out and lots of kids are going to Mexico. Therefore I am seeing a ton a basically good kids getting arrested for petty weapons violations.
In Cali it is illegal to carry a switchblade knife on your person or in the passengers compartment of a vehicle. CPC 653k is a misdemeanor that you will usually be ticketed for, but can be taken to jail for. Get yourself a nice Spyderco or Benchmade instead of that POS Chinese switchblade you are considering bringing back from Tijuana.
Brass knuckles are a felony here, CPC 12020, and you will be booked into the County jail. Even if you "bought them to made a belt buckle" for your white pleather belt you stole from you sister for the straight edge party. By the way, does you little sister know you are wearing her pants? Get yourself a D cell mag light for your car instead.
Batons or Billy clubs, including ASPs, tire knockers, fish billys, ect are also a felony. Again, get yourself a D cell mag light, a can of OC spray and a Spyderco instead. If you find yourself stopped by the police in possession of a club type weapon and the police ask you why you have it the wrong answer is " For protection" or "because some guys are after me." The correct answer is "it's just a flashlight sir" "its a fish billy sir" "it's a tire knocker sir" The section of law you are worried about is "the manner in which it is used defines the tool."
If you find yourself arrested for CPC 653k you are looking at about a $100.00 fine and a year informal probation most places. If you find yourself arrested for brass knuckle or a billy club you will be booked for the felony, but the DA will let you plead to a misdeanor. Again you are looking at a small fine, and probation. However, a term of your probation is likely to be "possess no weapons." You will also have search & seizure terms, which means the cops can search you, your car, or your house whenever they want to, for any reason at all, during your probation. So unless you want to lock up your guns in a storage locker for 1- 3 years during your probation, dont carry brass knuckles, billy clubs, and switchblades in public!