If you plan on making rings, you need to get a ring mandrel.
Metal Ring Sizer Mandrel True Size Steel Ring Mandrel from Kassoy
Ring Mandrel / Steel Ring Mandrel – uptowntools
Ring mandrel : r/3Dprinting
THIS METAL RING SIZER IS ALSO KNOWN AS A MANDREL AND CAN BE USED TO RESHAPE AND STRETCH RINGS AS WELL AS SIZE THEM. SOLID STEEL SIZES 1 - 15 WITH 1/4
Steel Ring Sizer/Mandrel with Sizes 1-15 SALE
PROFESSIONAL QUALITY RING MANDREL 1-16-MAN-295.00
11 Pieces US UK Ring Mandrel Set, Size 1-13 with Half Size Ring Sizer Gauge Ring Mandrel Jewelry Hammer Ring Sizer Adjuster Polishing Cloth Polishing Stick Polished Agate Knife Measuring Tool (Black)
69-174 EURO TOOL Stepped Ring Mandrel on Base - Rings & Things
What is a Ring Mandrel? Which One Should I Buy? - International Gem Society
13-1/2 Indexing Stepping Ring Mandrel
PrecisionFit™ Aluminium Marked Ring Mandrel (USA Size 1-16)
Otto Frei searches the world over for the best quality jewelry products and this steel ring mandrel from India is the best of all the mid-priced ring
Steel Ring Mandrel Graduated In USA sizes 1 To 15 By 1/4 Size-No Groove