First of all I have to say that I only bought them because they were cheap and I don't have much experience with this type of cutter. I didn't realize the dimensions are diameters so that's my fault. But beware if you're looking for larger cutters. I had to take a closer look at the pictures. In fact, they are unable to shrink in any way. I used it on my CNC to try to plug it in. Bad idea. The welds that hold the blades in place extend to the tip, so there's no actual cutting edge there. If you just cut along the edges everything works fine, but the bottom of the groove can get burned if you're not careful.