A single-threaded power screw is 20 mm in diameter with a pitch of 7 mm. A vertical load on the screw reaches a maximum of 5 kN. The coefficients of friction are 0.06 for the collar and 0.09 for the threads. The frictional diameter of the collar is 45 mm. Find the overall efficiency and the torque to "raise" and "lower" the load. Give your answer to 3 significant figures.