Abstract: A surgical power tool in which a quick-lock latch mechanism permits attachment and removal of the drive shaft assembly with one hand and a seal arrangement effectively seals moisture from the bearing and motor compartments, yet creates only minimal drag on the motor. The power unit portion has a female end which receives the male end of the drive shaft assembly. Outwardly extending pins from the male portion pass through aligned notches in a rotatable cap portion and in the female end, and are locked in place by rotation of the cap. The seal consists of a nylon bushing on the shaft, slightly less in diameter than the internal bore of the tool, and a mica seal fitted within the bore but loosely on the shaft, the bushing and mica seal seating on each other when the tool is shut off to maintain an effective seal while the tool is inoperative.