These rings are made in the USA from 12 gauge stainless steel and are flat welded so there are no bumps that will impact the glass.
Stainless steel rings are great to use in many ways. You line them with 1/8” fiber paper and use for strip construction, combing, scrap melts, pattern bars, pot melt pot forms and as a dam for any fusing that is thicker then ¼”. Just lay the form with the fiber paper onto a kiln washed shelf.
Stainless steel rings are easier and cleaner than building dams that can collapse and make a huge mess in your kiln!
It is especially fun to experiment with flowing glass patterns using these rings.