| 摘要 |
An improvement in fuel economy and a reduction in manufacturing cost are realized by reducing a weight of a tool engagement portion and hence a weight of a housing. A glow plug 1 includes a cylindrical housing 2 having an axial hole 4 which extends in the direction of an axis CL1 and provided with, on an outer circumferential surface thereof, a screw portion 5 for being screwed into a mounting hole of an internal combustion engine, and a heater member 3 inserted into the axial hole 4 in a state where at least front end portion thereof projects from a front end of the housing 2. The housing 2 includes a tool engagement portion 6 which is provided at a rear end side than the screw portion 5 and to which a tool is engaged when the being mounted to the internal combustion engine. An inner circumference of the tool engagement portion 6 has a shape which follows an outer circumferential shape of the tool engagement portion 6. |
