TexasCHLforum.com

Personally, I have never seen a folding knife that opens using centrifugal force. Centrifugal (or centripetal for that matter) acts only in a direction away from or towards the point of rotation (the pivot pin in the knife) and as such cannot do any work causing a change in the state of a folding knife (unless the length of the blade changes resulting in a movement toward or away from the pivot pin) . The opening of butterfly type knife is due to the torque that the user applies to the knife which imparts angular momentum to the blade and handle. When the user applies a counter torque to the handle to stop its movement, the angular momentum of the blade causes it to continue rotating and open up out of the handle. To say this is opening with the application of centrifugal force has no basis in scientific fact. This is just another case where the lawyers tried to use a scientific term and got it wrong.