The only blade length mentioned in the SF Police Code is in a loitering law (Article 17, §1291). Arguably any pocket knife would also be covered there, regardle

The only blade length mentioned in the SF Police Code is in a loitering law (Article 17, §1291). Arguably any pocket knife would also be covered there, regardless of length, under "any cutting, stabbing, bludgeoning weapon or device capable of inflicting grievous bodily harm."