My jump rings are handmade. The wire is coiled on rods on a coiling machine, then the coils are machine cut on a small cutting saw using a .008" thick jeweler's blade, which guarantees the smallest possible opening in each ring. I designed and built both the coiling machine and cutting saw myself. The coiling rods I use are sized in true millimeter sizes. You have my guarantee that I never cut jump rings in Imperial Unit measurements (inches) that are then converted to the nearest millimeter size.
Silver-plated enamel-covered copper wire
4.5 mm (inside diameter)
30 jump rings
* Other quantities are available by special request. Don't hesitate to ask!