Abstract: A magnetic head positioning system operates with a lead screw stepper motor assembly and a recording or reading head. The lead screw of the lead screw stepper motor assembly extends through and coaxially with a hollow cylindrical tube. Two slots are provided through the peripheral wall of the tube and extend from one end of the tube towards the second end. A floating nut is shaped to be placed on the lead screw so as to move in a first and second direction as the lead screw is moved in a first and second direction by the motor assembly. The floating nut is provided with two outwardly extending wings, each shaped to fit in one of the slots provided in the tube. A carriage assembly is secured to the head and includes a tubular structure having an inside diameter larger than the outside diameter of the slotted tube. The tubular structure also includes two slots extending from one end toward a second end of the structure.