The new and improved Drive shaft is made out of Stainless Steel with a Hex Shank end for longer life and better Drill Grip with less slipping. These new Drive shafts screw into the new Cranks. These are now 2 separate pieces that can be replaced individually. If you have the old Aluminum welded shaft and crank to replace you will need to purchase both of the new shaft and crank. You will most likely not have to replace this part again.