An assisted-opening knife is a type of knife which uses an internal mechanism to open the blade from a closed position when slight pressure is applied to the thumbstud or other finger actuated device. When the knife is in the closed position, the blade is held in place by means of 1 or 2 torsion bars. As the user applies manual pressure to the thumbstud to open the knife, a mechanism such as a torsion bar moves along a track in the liner and rotates the blade into the open position.
Many folding knives feature spring assisted opening to make one handed draws easy and fast. Several knife manufacturers include spring assisted opening mechanisms in their line of knives. J&L carries brands such as Smith and Wesson, Tac Force and Taylor Schrade Brand to name a couple.
To read more about the differences between assisted opening and switchblades or to see law that was enacted to cover the differences please see our HELP section entitled Assisted Opening Knife Facts