Abstract: In a Hand-Held Extruder for polymeric materials such as elastomeric sealant compositions, an extruding barrel has, a material flow passage with an inlet for introducing the sealant material to be extruded into the material flow passage and a discharge outlet for discharging the sealant material, a thermostatically controlled heating mechanism for adjustably controlling the heat of the extruding barrel to maintain the material being extruded in plastic condition, and a screw type conveyor rotatably mounted in the extruder barrel for moving the plastic sealant material from the inlet to the discharge outlet of the material flow passage, the screw conveyor is driven by any suitable power source coupled to a double planetary gear reduction transmission assembly so as to provide a counterclockwise rotation of the screw conveyor without reduction in torque to increase the troughput and discharge of material from the material flow passage.