The machining of drills includes an operation for chamfering the cutting edges performed in two steps. The improvement according to the present invention is that at least two piezoelectric elements are longitudinal elements for longitudinal waves; and the first frequency is different from said second frequency. Another object of the invention is to provide waterproof and airvapor-proof details, a new concept of flashing and sealant application around windowsdoors and other constructive elements to avoid thermal bridges and air leakage inside thermal envelope and wall assembly. The symbols may be arranged horizontally, on multiple image planes, in close proximity to each other. Thus, when identification information on the subject is recorded in connection with the photographed image, the input of the identification information is simplified, and the correspondence between the subject identification information input before photographing and the subject to be photographed can be easily confirmed. Furthermore, an axial width Tc of the radial outer end portion having a substantially U-shape is equal to or smaller than 2.