Nope, it's definitely concave.It looks in the thumbnail like a Hunter carbide cutter, but when I enlarge the photo, it appears the inside of the cutter has a convex contour. Is this correct? A Hunter would have a concave inner contour.
Do you recognize the make of this hollowing tool? I'm trying to find a replacement for the 1-cm hollow-grind cutter and would like to get the right one.