Protective device for a male end portion of a steel tube for use in a tubular hydrocarbon working string, the device including a cylindrical sleeve body having a main axis and defining an inner cavity intended to receive the male end portion, an engagement portion having the cylindrical sleeve body is split axially in at least two shells being held together by a junction, and the engagement portion is so configured to separate the at least two shells under exertion of a predefined axial force on a first or second engagement surface.