>>gnabgi+(OP)
I'd be interested to know how BMW manufactures those screws. The patterns in the metal in the image suggest the entire hole was drilled out? The deepest part has circular marks inside that looks like the marks left by a facing tool on a lathe or similar. Then I guess the two wedges were inserted and the whole screw faced?
>>voidUp+Zj
I don't see any geometry that would be hard for casting or milling, it's slightly more expensive because you can't do it in one go, but you have to lift the toolhead if you mill.