Hard rock I think, but not metal. I don't think anything Deep Purple ever did really qualifies as metal. The concept of heavy metal as I perceive it wasn't really invented till sometime in the 1980s. I certainly can't remember ever hearing the phrase used to describe a music form until the advent of bands like Metallica et al. Even bands like Judas Priest and Sabbath in the 70s weren't described as heavy metal but as heavy rock.
Having said all that however i concede that as an old fart my memory might be slightly flawed and I might be talking just a load of old bollocks........