I discussed this topic with my attorney a while back. It was just conversation, I wasn't actually interested in carrying a blunted concealed fixed-blade.
Here is what my lawyer basically told me- There are fixed-blades that are clearly not designed for stabbing, and some that would not make effective stabbing weapons (cleaver-type blades, some skinning knives, some diving knives, etc). And my attorney was confident that if one of his clients were in possession of one, and if they were arrested and charged with carrying a concealed "dirk" or "dagger", that he could either get the charge dismissed, or win at trial*, or win on appeal*.
His reasoning was- If the knife clearly does not meet California's legal definition of a "dirk" or "dagger" (stabbing weapon), then there is a very real possibility of the charge being dismissed. Prosecutors tend to have a heavy case load and don't want to waste time trying to prosecute a charge if they don't think they will win, or if they think it will be reversed on appeal. And if the defendant has no criminal record, and wasn't engaged in any criminal activity at the time of their arrest, that gives the prosecutor more incentive not to take the gamble.
My attorney also told me that the California appeals court has a history of being hyper-technical when it comes to knives and their design. He was confident that a knife which was clearly not designed as a stabbing weapon, and clearly would not make an effective stabbing weapon, would not be ruled a "stabbing weapon" by the appeals court, and thus the conviction would be overturned. This is all something that a good defense attorney would relate to the prosecutor.
He also explained to me that here in California a prosecutor has three burdens of proof that they need to meet in order to obtain a sustainable conviction for carrying a concealed "dirk" or "dagger". There is case law on this but I forget the name at the moment-
1. The item (not necessarily a knife) must meet the legal definition of a "dirk" or "dagger".
2. The person carrying the item had to acknowledge in some way that they were carrying the item as a weapon, OR that they knew the item could be used as a weapon. However, the prosecutor does NOT have to prove that the person had intent to USE it as a weapon.
3. The person had to intentionally try to conceal the item on their person.
In regards to #1, the appeals court rejected a particular knife as a "stabbing weapon" because the judges did not believe that the knife would make for an effective weapon to stab people. My attorney believes that they would feel the same way about a knife with no point whatsoever (like the ones mentioned earlier).
In regards to #2, there are specific exceptions in the case law for things like- a person who was using a knife for work, stuck the knife in their pocket, and forgot it was there, and it got covered by a shirt, etc. Or, someone who wrapped a kitchen knife in a paper towel, and placed the knife in their jacket pocket to use it at a later time for food prep (as I recall, these are actual examples provided by the appeals judges). Another example would be someone who puts a pair of scissors in their pocket, or sticks a screwdriver in their waistband. Basically, the judges wanted to provide protection for people who were carrying items that could be used as stabbing weapons, but who were carrying them for purposes that are both practical and innocent.
In regards to #3, as I recall, the appeals judges provided specific exceptions to protect people who were carrying an item that could be used as a stabbing weapon, but the item became unintentionally concealed by clothing (like wind blowing a shirt).
So, as my attorney explained it to me, as long as a person was carrying a fixed-blade concealed that was clearly NOT designed as a stabbing weapon, and did not appear to be reasonably capable of being an effective stabbing weapon, and as long as the person carrying it did not in any way refer to it as a weapon, or even acknowledge that it could be used as a weapon, that he could eventually* get the person off.
But here's the thing*- there is no certainty in the criminal justice system. Although my attorney is confident, his confidence is not the same as certainty. He readily acknowledges that no matter how good a defense attorney is, that they cannot control what a judge, prosecutor, or jury will do. And no matter what the case law says, some prosecutor might try to challenge it, and a judge might let them.
I once asked my attorney a question about knives, and I asked if there was any case law, and he answered "No. Do YOU want to become the case law?" My answer was "No".
Here's the advice my attorney gave me- Don't test the law. Even if you eventually prevail in court, it will cost you a hell of a lot. It will cost you a lot of money, a lot of stress and aggravation, and a lot of time. You could miss a lot of work and lose your job, miss a lot of school and not graduate, and you could spend some, or a lot of that time behind bars. Or, you might lose altogether.
So, don't carry ANY fixed-blade, or screwdriver, or any other seemingly "dangerous" item concealed upon your person if it could be used as a "stabbing weapon". And before anyone asks, no, a pen or pencil would not be considered a "stabbing weapon" if carried concealed.
). I'll have to look that one up when I get the time, it looks like good reading.