Self-Supporting Pyrometric Cones are used on a shelf inside a kiln or in a kiln sitter to determine when a firing is complete, if the kiln provided enough heat or if there was a problem during the firing. Orton cones are made from carefully controlled compositions so that they bend in a repeatable manner over a very small temperature range. The cone tip sags until it reaches a point level with the base indicating the kiln has properly fired. Cones have been used in ceramic firings for more than 100 years and Orton has the history and experience to provide the very best product. The number of this cone is 04 which bends at an approximate temperature of 1940° F, depending on firing conditions.