That's what I need. AccuSize doesn't stock them. Where? Actually, I am going to go measure it. I don't think one end is tapered at all. AccuSize is all Chinese, and the guy I was talking to spoke and understood English poorly. Just measured it, and the end going into the tapping head is definitely JT6.
Perhaps an adapter? JT6 to MT2 and MT2 to JT3?