Well, they obviously might be - that depends upon whether there is a satisfactory "first part of double insulation".John, No, I'm asking if the plastic bodies of e.g. vacuum cleaners and drills are the second part of double insulation.
As I said, in the case of a drill, there might be a metal chuck (or metal parts of a chuck) which are touchable without any insulation between it and the user - so, in that case, it would presumably have some sort of "double insulation' within the drill (if it were Class II).
As I also said, in terms of satisfying the requirements for Class II status, true 'double insulation' seems much less common than reliance on 'reinforced (single) insulation'.
Kind Regards, John