Spring-Assisted Knives are Illegal in California. It should also be noted that a pocketknife that was legal when manufactured, but is broken or modified so that it will open freely, is a switchblade within the meaning of the statute.Click to see full answer. Similarly one may ask, is it illegal to have a spring assisted knife?It means a super fast opening blade using just one hand and Spring Assist Knives are 100% legal to own in all 50 states but your local laws might restrict them from being carried into public or might have concealment or non-concealment laws. You can read the law at Assisted Opening Knives Law.Likewise, what kind of knives are illegal in California? California’s law prohibits carrying concealed “dirks” and “daggers.” Dirks and daggers are knives capable of causing serious injury by stabbing. Illegal knives include: switchblades, ballistic knives, and. “novelty” knives, such as belt buckle knives and cane swords. Beside this, what states are spring assisted knives legal? State Laws Regarding Auto-Open Knives Alabama. Alaska. Arizona. Arkansas. California (less than 2″ blade length limitation) Colorado (effective approximately Aug. 9, 2017; concealed carry maximum length 3-1/2″) Connecticut (maximum 1-1/2″ blade length limitation) Florida. Are double sided knives illegal in California?There are no state laws in California that prohibit the sale, purchase, possession, or OPEN CARRY of double-edged fixed-blades. It is illegal to carry them concealed. There are also no state laws prohibiting the sale, purchase, possession, or carry (open or concealed) of double-edged folding knives.