The specifications according to this standard apply to brake drums and brake discs of drum brakes and disc brakes in driving gears in the field of power transmission engineering. This standard has the purpose to attain sufficient durability and to show possible waxs to increase the service life of brake drums and brake discs. Within the meaning of this standard, brake drums are part of the equipment of external double jaw drum brakes and brake discs of the equipment of external double jaw disc brakes.#,,#