I want to attach some 2" plastic pipe to a 11/2" metal drain pipe

Hi Matt01,

You should not connect larger pipe into smaller pipe. It should go the other way around.

In any case, you can purchase Fernco / ProFlex coupling to connect those two. See the pic. One end of this coupling fits 2" plastic pipe and the other will fit 1 1/2" metal pipe.

Moreover, there are few "metal" pipes. Each has different O.D. ( cast iron, galvanized, copper, black pipe etc. ). You should know what "metal" pipe you are working with and buy the coupling accordingly. Same goes for "plastic" ( ABS, PVC, tubular ABS etc ).

Some Home Depots carry these couplings.