A festive lamp finial is the perfect way to complete your holiday decorating routine. A quality finial that is sure to dress up your lamp for the holidays. Finials have a standard 14-27 thread, which will fit the harp on almost every lamp. This means the opening is 14 wide and there are 27 threads per inch. 95% of all lamp harps will fit this finial. A festive lamp finial is the perfect way to complete your holiday decorating routine. A quality finial that is sure to dress up your lamp for the holidays. Finials have a standard 14-27 thread, which will fit the harp on almost every lamp. This means the opening is 14 wide and there are 27 threads per inch. 95% of all lamp harps will fit this finial.