Arranged in the bottom of a cup-shaped cylindrical casing is a solid disc form of axially uniformly magnetized permanent magnet having a single pair of poles each formed on one or the other of its opposite end faces over the whole region thereof. A circular plate of magnetically permeable material is fixedly mounted on the magnet and to which plate a set of coiled posts are fixedly fitted. The casing is preferably formed on its outer periphery with cooling fins for dissipation of heat generated therein during printing operation. The magnet and the plate thereon, identical in outer diameter, are radially spaced an appropriate slight distance from the inner wall surface of the casing to form a bypass circuit for the flux of the magnet. Arranged in the open top of the casing is a spring-charge type print hammer assembly which includes a radial array of resilient tongues (hammers) and print wires secured thereto preferably through the medium of flat armature plates fixed to the respective tongues. The print head is particularly suited for high-speed printing operation with low power requirements and, owing primarily to the extremely simplified form of magnet used, is of reduced fabrication cost. The armature plates, in cooperation with a yoke plate slotted to receive the plates serve to compensate for any possible increase in reluctance of the main magnetic circuit and increase the kinetic energy of the tongues or print hammers when released.