What materials are used in general automobile carburetors?

Take the carburetor of the oldest Dongfeng, Jiefang and Beijing Jeep gasoline vehicles as an example. The upper and middle parts are made of aluminum. The measuring hole and nozzle are made of copper, and the throttle valve and baffle are made of steel. The lower body is cast iron; Float is plastic (the old float was hollow copper, which was later replaced by plastic)