A knife include a handle, button, blade with an integral tang, locking mechanism within the tang, and thrust mechanism. The blade moves between closed and open positions. The button may axially slide along the handle. When the blade is in the closed position and locked, movement of the button towards the first handle end releases the locking mechanism and the thrust mechanism moves the blade to the open position. A knife includes a stop pin connected to a tang of a blade and a stop plate positioned within a knife handle. The stop plate has two angled surfaces. The stop pin mates with both angled surfaces and the blade is constrained from movement in two planes.