Abstract: A mechanical hand assembly for use in prosthetic and robotic applications includes multiple fingers pivotally attached to a palm subassembly. The fingers are operatively attached to a central actuating plate so that movement of the actuating plate in opposed directions causes the fingers to bend and straighten. An electric motor drives the actuating plate through a pivotable or tiltable linkage so that when one of the fingers engages an object to be manipulated, the plate tilts and continues to move any opposed fingers toward engagement. Each finger includes a base, a lever arm and multiple phalanges operatively interconnected by gears. Pivotal motion of the lever arm is transmitted to the phalanges through the interconnected phalanges and lever arm and rotation of the gears.