Abstract: A dry type, air cooled transformer having a mitered magnetic core and a compression bonded coil. In the disclosed embodiment, the magnetic core comprises a plurality of stacked lamination layers wherein each layer comprises a plurality of grain-oriented laminations wherein the ends of most of the laminations are mitered thereby resulting in joints between the leg and yoke pieces oriented at an angle to the favored magnetic directions of the adjoining laminations. The coil on each of the core legs is generally rectangular in shape and comprises a plurality of layers of wound conductor with the conductor layers in the end portions of the coil being spaced apart to form a plurality of air ducts for the passage of cooling air therethrough. The conductor layers in each of the side portions of the coil are compressed and then bonded together in their compressed state by means of a heat cured adhesive coated on opposite sides of the sheets of insulation between adjacent layers.