Do the physical properties of Ap binaries depend on their orbital elements?

We reveal sufficient evidence that the physical characteristics of Ap stars are related to binarity. The Ap star peculiarity [represented by the Delta (V1 - G) value and magnetic field strength] diminishes with eccentricity, a nd it may also increase with orbital period (P-orb). This pattern, however, does not hold for large orbital periods. A striking gap that occurs in the orbital period distribution of Ap binaries at 160-600 d might well mark a discontinuity in the above-mentioned behaviour. There is also an interestin g indication that the Ap star eccentricities are relatively lower than thos e of corresponding B9-A2 normal binaries for P-orb > 10 d. All this gives s erious support to the pioneering idea of Abt & Snowden concerning a possibl e interplay between the magnetism of Ap stars and their binarity. Neverthel ess, we argue instead in favour of another mechanism, namely that it is bin arity that affects magnetism and not the opposite, and suggest the presence of a new magnetohydrodynamical mechanism induced by the stellar companion and stretching to surprisingly large P-orb.