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.Click to see full answer. Also know, 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 above, are daggers illegal in California? CALIFORNIA. In California, folded pocked knives are legal, but it is illegal for any person to concealed carry any knife legally described as a “dirk” or “dagger” — the legal terms for any fixed-blade knife or stabbing weapon. See § 12020(4). Even a locked pocket knife can count, so can a screwdriver in some cases. In this manner, is a double edged knife illegal? It is illegal to carry (either concealed or otherwise) dirks, stilettos, daggers, a double-edged non-folding stabbing instrument of any length or any other dangerous weapon in any vehicle occupied or operated by the person. With the exception of a hunting knife adapted and carried as such.How long of a knife can you carry in California?For state or local public buildings, it is illegal to carry any knife with a blade of more than 4 inches onto the premise. California Penal Code Section 171b.