What Are These Little Carb Bits?

[Mitragorz]

I just received a nice set of disassembled carb bodies from a kind fellow (aviationfred) on Facebook.  There were three of these little buggers in with all the rest of the little bits, and I have no idea what they are.  Looks like they may have been pressed out from somewhere?

[petetb154]

Almost certainly they are the plugs installed on top of the air screws. The air screws are on the top of the carb, forward of the throttle butterfly valve. The plugs are removed with a drill and easyout or taps. Then the screws can be adjusted and/or the carbs cleaned. 

[Mitragorz]

Makes sense.  Carbs I'm used to working on always had actual caps... you'd drill a small hole, thread in a screw, and pop it out.

Thanks