Self-Supporting Cones are the most accurate and easiest to use witness cones available. They provide the same information as Orton Large Cones. The advantage of Self-Supporting cones is that they are the correct height (1 3/4″ exposed above the base) and have the 8 degree bending angle built in. They do not require plaques. Self-Supporting cones can be set on any flat surface.
Self-Supporting Cones are available for use between 1087F and 3106F (586C and 1708)C. Cones are numbered from 022 to 32. Cone 022 is the cone that will deform at the lowest temperature (1087F) and cone 32 is the cone that deforms at the highest temperature 3106F (1708C).
Self Supporting Cones are recommended by glaze and kiln manufacturers to achieve the best results.