Review on Ring Sizer Mandrel Tool Kit - Iron, Steel, and Plastic Measuring Gauge for Accurate Finger Sizing, Including 3-Piece Jewelry Polishing Cloth and Metal Measurer by Carrie Spencer

Here's the thing - this sizing machine isn't perfect, but the size of the rings isn't perfect either. The key issue that I think most people overlook is that the wider the ring, the tighter it will feel. So a size 7 ring that is 2mm wide is much looser than a size 7 ring that is 6mm wide. I have tested this mandrel with rings of known sizes. The correction was accurate. The ratio of numbers to lines is a little shaky, but if you use a ring of a known size, you'll understand what a half size is compared to a whole size. Then, after making sure the mandrel was accurate, I checked the ring gauge on the mandrel. Exactly too. Maybe sometimes 1/4 size too small, but ok, that's enough. The same applies here: A wider ring is worn tighter. This is also reflected in the use of the mandrel. The bottom edge of my 8mm ring was hanging "higher" on the mandrel than my 4mm ring, which makes sense when you think about it. So you can use the bottom edge to determine the true size of the ring. Just keep these things in mind when using them and you will get accurate results!