| 摘要 |
In a spark plug, at a cross section of a ground electrode which is orthogonal to a longitudinal direction of an electrode base material and passes an axis of an electrode tip, a surface of the base material is exposed, and the following conditions are satisfied:
1.2E ‰¤ F ‰¤ 1.9E; 0.05 mm ‰¤ Da ‰¤ 0.30 mm; 0.05 mm ‰¤ Db ‰¤ 0.30 mm; and
0.20 mm 2 ‰¤ J ‰¤ 0.70 mm 2 . |
