How do major manufacturers do it? Thumb studs

[OfficerCamp]

Couldn't really find an answer to this question. How do major manufacturers (benchmade, ZT etc) put thumb studs on their blades? I know some of them are attached with screws and are removable, but what about the ones that are permanent? Are they integral with the blade (ie milled out with the blade?)
Just curious.
OC

 

[fishface5]

not integral that would waste too much steel. Possibly press-fit.

 

[brownshoe]

Chris Reeve Knives studs are press fit. Most of my others are screwed in or have a nut/screw. None I've seen have been milled out of the blade.

 

[Scurvy092]

It would be insanely expensive to buy such a thick piece of steel only just to mill away 50%+ of it. The steel cost would be huge and the milling would take hours of man/machine time.