zlacker

>>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
The prototypes might be milled and/or produced via additive manufacturing (3D printing.) In production the heads are likely formed via stamping. Here's an old video I remember watching as a kid (Unfortunately quite pixelated) of the Robertson screw being manufactured which has a tapered square profile for the bit: https://www.youtube.com/watch?v=Td7GjAMAY7Y (The Acme School of Stuff was awesome for its time and still is.)