Abstract: A utility knife having a casing, a blade holder moveably mounted within the casing, the blade holder is moveable incrementally from a fully extended position outside the casing to a fully retracted position inside the casing so that the blade holder may be positioned in a partially extended position.

Abstract: A hack saw having a blade holding assembly and a blade lock assembly. The blade lock assembly having moveable blade lock means adapted to receive a blade therebetween, mechanism for moving the blade lock means to a position to hold a blade in place.

Abstract: A utility knife having a handle and a blade holder which is pivotally mounted on the handle for movement from an unfolded position to a folded position. The handle has a space adapted to receive the blade holder when the blade holder is in its folded position. A spring pressed lock plug is provided to move into and out of the space to hold the blade holder in the folded and unfolded positions. The blade holder includes a main wall and guard wall pivotally mounted on the main wall to pivot from an open position to a closed position overlying the main wall. The main wall being adapted to hold a blade so that a blade is interposed between the main wall and guard wall when the guard wall is in its closed position.

Abstract: A foldable knife having a handle and a blade holder movably mounted on the handle for movement from an unfolded position to a folded position. The handle has a space adapted to receive the blade holder when the blade holder is in its folded position. The blade holder has a blade locking mechanism.