Abstract: A plurality of magnetic head cores is cut from a preprocessed ferrite core block having a gap formed by means of a fracture method. To this end the core block is notched on a line along which the gap is to be formed. subsequently the core block is subjected to a load (tensile stress) until it breaks on the line. A non-magnetic material in a liquid form is provided between the fracture faces which are kept at a desired distance from each other until the material has cured. In a preferred method the core block consists of a first sub-block having a series of yokes and a second sub-block bonded thereto to define the winding apertures. This permits use of a high grade ferrite only at the gap, and further permits winding the limbs of the yoke prior to bonding.