In general, the opening and closing speed of a folding knife cannot be adjusted as it is primarily determined by the specific design and mechanisms used in the knife. The speed at which a folding knife opens and closes depends on factors such as the type of opening mechanism (e.g., manual, assisted, or automatic), the type of pivot system, and the internal springs or mechanisms used.Manual folding knives rely on the users manual effort to open and close the blade, so the speed is entirely under the control of the user.Assisted opening knives typically incorporate a mechanism, such as a spring or torsion bar, that assists in blade deployment after an initial manual opening. While the assisted opening feature can speed up the opening process, the speed is generally fixed and cannot be adjusted.Automatic or switchblade knives are designed to open with the press of a button or lever. The speed of opening is determined by the internal mechanisms and springs, which are typically set to a specific speed and cannot be adjusted by the user.However, its worth mentioning that the smoothness of the opening and closing action can be influenced by regular maintenance, lubrication, and adjustments made by a professional knife technician. These maintenance practices can help ensure the knife operates smoothly and reliably over time.