JDG ring Crafters expanding ring mandrel – Ringsupplies.com
Amazon.com: Expanding Stainless Steel Ring Mandrel for Ring Turning and Ring Making. (Ring Sizes 11-14) : Arts, Crafts & Sewing
Amazon.com: Expanding Ring Mandrel with Hex Allen Key – Set of 3 Premium Steel Ring Mandrels for Lathe – Heavy Duty Ring Shaper Tool for Ring Turning and Ring Making – Ring
Stainless Steel Ring Mandrel 9-13 at Penn State Industries
Expanding stainless steel ring mandrel for lathe and wood rings – Ringsupplies.com