A. Probably not. In the plumbing trade when we say 1/2" fittings we mean fittings that use 1/2" nominal pipe. To figure what size pipe to use with standard plumbing fittings, you must add 1/8" to your measurements to know the o.d. (outside diameter) of the pipe. 1/2" nominal fittings use 5/8" od pipe; 3/4" fittings uses 7/8" pipe and so on.