摘要 |
An earth bolt is capable of achieving electrical connection and watertight sealing and of holding fragment of a coating so that the fragments of coating may not be scattered. The earth bolt can be electrically connected to a member coated with an insulating film. The earth bolt has a head and a threaded body. The head is provided on its bearing surface with an annular ridge protruding from the bearing surface of the head so as to coaxially surround the threaded body and capable of scraping off the insulating film. |