| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a spark plug capable of securing anti-loosening property of a main metal fitting that is fixed by screwing in a mounting hole with a sealing member interposed. <P>SOLUTION: In the process of screwing the main metal fitting 50 having an Ni-plating layer formed on the surface into the mounting hole 91, in a state where a gasket 60 made of a stainless steel is interposed between an overhang portion 54 and an opening edge 92 but not compressed, the surface of the gasket 60 is not in contact with surfaces in other portions of the gasket itself. When the gasket 60 is viewed in a cross section in the direction of an axial line O, the gasket 60 and the overhang portion 54 are in contact with each other at one point P, and the gasket 60 and the opening edge 92 are in contact with each other at one point Q, wherein the point Q is located radially outside the point P. The point Q is located radially inside the largest outer diameter Dz of a seat face 55 of the overhang portion 54. <P>COPYRIGHT: (C)2012,JPO&INPIT |
