Abstract: A screwable device having a retractable threaded section that has a generally tubular shaft extending along a longitudinal axis and having a front section formed with a radially outwardly open aperture and a rear section. At least one locking element comprising a threaded section and being radially displaceable in the aperture between an outer position with the threaded section projecting radially outward from the shaft and an inner position in which the threaded section is recessed within the tubular shaft. An actuating is rod coaxially slidable in the shaft between a front position and a rear position, the actuating rod having a push-button at its rod rear end, the actuating rod having a structure for engaging the locking element in at least one of its positions pressing the locking element into the outer locking position.