Abstract: An electric starter solenoid for starting internal combustion engines includes a housing having a lower coil section and an outer rectangular contact section. The coil section has a hexagonal cross-section and a depth to receive an annular coil unit. An armature is journaled in the coil unit. A contact guide with spaced terminals to the opposite ends in the upper section. A floating contact plate is resiliently mounted on a guide pin and guided in the rectangular section. The guide pin engages the armature. A light spring urges the guide pin against the armature in spaced relation to the terminals. The coil unit includes a bottom plate with opposite projection mating with corners of the housing to angularly orient the coil unit in the housing. In one unit, a common coil lead is connected to the bottom plate.