A tire rim structure and method of manufacture in which rows of sharply edged or pointed projections are integrally provided on the ear portions or bead seat portions of the rim. In accordance with the preferred embodiments of the invention, the projections may be pyramid shaped, triangular prism shaped or sawtooth shaped. The projections may be formed by applying a triangularly toothed roller or a grinding device to elongated ridges formed on the tire rim during an otherwise conventional extrusion process for obtaining a smooth tire rim.