A dot matrix print head in which the mass of the armature is reduced by providing a groove in the armature in the portion where the magnetic flux density is relatively low. The armature may be advantageously attached to a sheet spring by laser welding applied from the bottom surface of the groove without creating craters in the external face of the sheet spring. Reduction in the mass of the armature allows a substantial increase in the print speed of the print head. Use of laser welding reduces the manufacturing cost of the print head and the absence of any craters in the external face of the sheet spring is favorable for the performance of the magnetic circuit of the print head.