Whats your point? Plastic forks and knifes are obviously no problem to possess, they have a utility purpose. That's my point their is no utility purpose with plastic knuckles. Even if they are plastic they are clearly still only a weapon
Where in the criminal code is it written that anything must have a utility purpose in order to not be considered a weapon? Most things in out modern have no or little utility purpose.
The reason why the list of prohibited weapons is so long is specifically because anything not on it is deemed not being a prohibited weapon. Actually, the fact that brass knuckles are on the list of prohibited weapons, and specifically defined as made of metal, would indicate that an item of the same shape made of any other material is specifically intended to not be a weapon.
As for article 90 of the criminal code (Carrying concealed weapon), section 2 of the CC defines what a weapon is:
“Weapon” means any thing used, designed to be used or intended for use
(a) in causing death or injury to any person, or
(b) for the purpose of threatening or intimidating any person
and, without restricting the generality of the foregoing, includes a firearm
Honestly, anything that's not readily visible can be considered a concealed weapon if you use it, or intend to use it, to cause death or injury to any person. That includes your belt, your keychain, your underwears, your wallet or phone, etc... Proof of the purpose for possessing the weapon may be established by the manner in which the weapon is used, circumstances and statements surrounding its use and the rational inferences to be drawn from the facts.
So yeah, a cop could arrest you for carrying a g10 knuckle under the pretense that he believes you have the intent to harm someone with it. Depending on the circumstances, you could be charged. For example, if you're in a bar trying to start a fight, or in a dark street following someone. But a cop that would just arrest you for carrying one of these as a keychain on a normal day would be a total ####, and at that point, he could just as well arrest you and charge you with any of the laws or bylaws that cops routinely use to harass people, and it would be more effective.
On a side note, the people who have been searched multiple times by cops in canada might want to rethink some of their life choices. Just saying.