| 摘要 |
PROBLEM TO BE SOLVED: To provide a long-life glow plug good in productivity by suppressing the occurrence of cracks at a melted portion.SOLUTION: A glow plug includes: a metal-made resistive heating element; and a sheath tube including a tube section comprising a Ni alloy containing Ni as a main constituent, disposed on the outer periphery of the resistive heating element and extending in an axial direction, and a melted portion containing at least the main constituent of the tube part and a main constituent of the resistive heating element and closing the tip of the tube part. The melted portion contains 0.03 mass% or more and 0.1 mass% or less, and has a Vickers hardness of 150 Hv or more and 350 Hv or less. |
