Pepetools newest line of Gold Standard Ring Mandrels ensure 100% match between any Pepertools Gold Standard Product. This means each Gold Standard Mandrel, Steel and Aluminum, and Gold Standard Ring sizer is assured to have 100% match. Each mandrel is inspected with a laser scan micrometer ensuring accuracy as well as verified with a ring sizer manually. The Gold Standard Steel Mandrels may be used at the Jeweler's Bench to do needed adjustments, repairs and custom made rings. The Hardened Steel Ring Mandrels are 44HRC Rockwell and will not deform easily, withstanding the striking of rawhide or plastic mallets. This hardened steel mandrel has no groove . Each Mandrel is packaged in a reusable plastic tube for easy transport without damaging the mandrel itself.