A folding knife includes a blade cavity defined by two liner plates into which a pivotal blade may reside. The blade, which is pivotally attached to liner plates at a pivot point, includes a tang having a recess that is parallel to the sides of the blade. A rod is pivotally secured to the blade within the recess. A spring is secured to either or both liner plates at one end and to the rod at the other end so that a pulling action is applied to the blade. The rod is attached to the blade with respect to the pivot point so that the action of the spring forces the blade into the blade cavity until the blade is rotated from the cavity past a critical point of angular displacement, after which the spring forces the blade to its fully open position.The invention further includes a variety of locking arrangements which ensure that once the blade reaches its fully open position, the blade will remain there until the user desires to close it.