An improved plier tool having a pair of crossed handle members each having a jaw at one end. The first of said handle members having a circular bore therethrough with the bore having an inner surface providing a first cam surface. A first disc-shaped cam positioned within this bore for rotation. The first cam further having an axle pin eccentrically mounted to the first cam and fixedly mounted to the second of said handle members. Further, a guide cam pin carried by the first handle member is positioned in spaced apart relation to the bore carrying the disc-shaped cam. A slot formed in the second member is spaced apart from the axle pin and is positioned to receive the guide cam pin. The slot having a second and third cam surface for bearing against the pivot pin. The first cam surfce in the first member and the second cam surface in the slot being respectively shaped to guide the jaw portions of the crossed members to maintain a substantially parallel relationship of the jaw portions when the pliers are being opened. The first cam surface and the third cam surface being respectively shaped to guide the jaw portions of the crossed members to maintain a substantially parallel relation when the jaw portions are being closed.
