I need an external male 48178condensation flow pipe with an elbow on it to connect to the internal condensation flow pipe to water can be directed to a drain. Someone said a 3/4 inch pipe would work but it didn't. I think the 58STA/STX uses a different measuring unit, more like metric I think.

That is an internal pipe thread fitting. Can't tell the size but it is probably 3/4". Get a 3/4" and a 1/2" pipe nipple about 3 or 4 inches long. Screw the appropriate pipe nipple into the fitting to clean out the threads of the fitting. Remove the nipple and then screw in the proper size PVC male adapter. After installing the PVC adapter, glue up the PVC piping to where you want to drain.

Never heard of a US air conditioner coil using metric fittings.

1/2 or 3/4" male IP adapter to PVC pipe.