Abstract: A cutting tool having a blade and a member which is biassed toward a safety position, in which the member forms a guard for the blade, but which may be displaced for exposing the blade by bringing the tool into cutting contact with a workpiece. The cutting tool includes a locking mechanism having a trigger which must be moved from a first position to a second position to release the guard member from its safety position and which is arranged, so that each time the guard member is released from its safety position, it is displaced through a predetermined distance and then returns to its safety position. The guard member will become locked in place regardless of the position of the trigger.