Stock #68 - 31mm round. 12mm hole. The thickness is 6mm at the inner hole and it slants down to 4mm at the outer edge. Very unusual shape. Authentic RARE vintage Bakelite! Great for all sorts of jewelry and accessory designs! These Bakelite ring components were found in the famous vintage bead hoard. Why is Bakelite so special? It was invented in 1908 and produced through the 1930's. Bakelite was called the material of a thousand uses. Bakelite was only made for a short period of time and there is no other material out there that compares! The feel and look of Vintage Bakelite is what has intrigued us here at A Grain of Sand. Authentic Bakelite is not not so easy to find. We are happy to say that these Bakelite beads and components are now available right here! All of our Bakelite has been tested for authenticity.