| 摘要 |
PROBLEM TO BE SOLVED: To provide a wood screw improvable in the finishing of an external heat insulating structure after fastening by setting the pitch of an underhead thread part appropriately. SOLUTION: The wood screw 1 for connecting lower wood 10 to a plate 30 through a heat insulating material 20 includes a shank 2 formed with a head 3 on the base end side; a main thread part 4 fastened to the lower wood 10 when connected; and the underhead thread part 7 fastened to the plate 30 when connected. The pitch P2 of the underhead thread part 7 is the pitch P1 of the main thread part 4 or less. The pitch P2 of the underhead thread part 7 is thus set to the pitch P1 of the main thread part 4 or less to prevent ventilation furring strips 30 from spreading from the heat insulating material 20 with the rotation of the wood screw 1. The finish of the external heat insulating structure after fastening is completed can thereby be improved, and efficiency in fastening work can be improved. COPYRIGHT: (C)2011,JPO&INPIT |
