MAGNETIC HEAD AND ITS PRODUCTION

PURPOSE:To stabilize the electromagnetic conversion characteristics of the magnetic head and to improve its yield by exactly finishing a depth length to a prescribed size. CONSTITUTION:A reference groove 22 is provided in the position apart a regulated size(a)from the depth length deepest position 0 of a magnetic gap 20a on the side of a second core part 12B constituting a main core 20 opposite to the magnetic gap 20a. This reference groove 22 is packed with glass 29. The reference groove 22 is a groove for estimating the depth length deepest position 0. As a result, the depth (b) is known by the width (c) and inclination angle thetaof the reference groove 22. The size obtd. by adding the size (b) and the size (a) is the distance from the end face on the reference groove 22 side to the depth length deepest position. Then, the depth length deepest position 0 is exactly estimated by the known size (a), the angle theta and the measurable size (c) even if the magnetic gap 20a is invisible by being concealed with a slider, etc.