I was told quite a few years ago by my Jamone serviceman that I shouldn't use the metal ones in my 9000 b/c of a magnet in the bobbin case and that it wouldn't spin right( I hope I'm remembering correctly) I guess my advice to you is use what came with your machine and/or check with your serviceman to see what they say. This particular guy also said to only use Organ needles in it b/c that's what he adjusted it to when he checked my machine. But the place I take my machines to now says I can use Janome, Schmetz or Organ.