My first thought is that I'm looking at a suboptimal outcome of some sort...
As to hints--we like to flounder about...
It sure looks like the finished product of two eggs easy over that my first ex wife used to cook for me,.. once.
I will say that suboptimal outcome is kind of right.Carbon brush?
Whatever it is, my condolences.
No combustion, but it can be used in things that involves combustion.Is combustion involved with this object? Something that burns or is very hot?
Neither hex nor key, (hex - 2 is more like it).Hex key?
Not a plug as been said earlier, not even a glow plug, we have already dispensed with things having to do with combustion or being very hot.Glow plug from a diesel?