Abstract: A supporting body member is arranged to be secured to a vehicle frame and has a downwardly angled flat wall portion on which one end of an arm carrying a step plate is pivotally attached. The axis of the pivot connection for the step arm extends at right angles to the downwardly angled wall portion so that when the arm is swung out to a use position the step plate is in a lowered position and when swung rearwardly to a non-use position the step plate is elevated. The body member has an upwardly directed front flange forming a stop for the step arm, and a detent is located on the flat wall portion behind the step arm to hold the latter in its use position, the arm being arranged, however, such that it can move rearward over the detent in the event that the arm or step plate is struck from the front or in the event that it is desired to retract the step manually.