at one end of the bed (almost always the left, as the operator faces the lathe) is a headstock. the headstock contains high-precision spinning bearings. rotating within the bearings is a horizontal axle, with an axis parallel to the bed, called the spindle. spindles are often hollow and have exterior threads and/or an interior morse taper on the "inboard" (i.e., facing to the right / towards the bed) by which work-holding accessories may be mounted to the spindle. spindles may also have exterior threads and/or an interior taper at their "outboard" (i.e., facing away from the bed) end, and/or may have a hand-wheel or other accessory mechanism on their outboard end. spindles are powered and impart motion to the workpiece.