(I'm in USA, talking about a Medium base/E26, not sure if it matters)

I know they're supposed to be captive and shouldn't come out, but my gf had a lamp take a fall and seems to have lost one of the terminal screws on the lamp socket. As I'm out of town, I figure it would maybe be easier to have her run to the hardware store and grab a few screws instead of trying to talk her through replacing the whole socket.

If it makes a difference, it's a 3-terminal socket (one click of the switch turns on top socket, another click turns top off and bottom on, another click turns both on, another click turns all off).

Are these standard, or does it usually vary fixture-to-fixture? And are they the same as screw terminals in an outlet?