Free reference
Cone Temperature Chart
Orton cone numbers against temperature, and what each one costs you in element life. Cones measure heat work rather than temperature, so these are the values at a 60 °C per hour climb — the rate most studio controllers use near the top.
| Cone | °C | °F | Typically used for | Element life |
|---|---|---|---|---|
| 022 | 586 | 1087 | Low-temperature overglaze and lustre | very long |
| 020 | 626 | 1159 | Overglaze, decals | very long |
| 018 | 686 | 1267 | Overglaze, enamels | very long |
| 016 | 745 | 1373 | China paint, lustre | very long |
| 014 | 794 | 1461 | Low-fire decoration | very long |
| 012 | 838 | 1540 | Low-fire decoration | long |
| 010 | 887 | 1629 | Low-fire glaze, raku | long |
| 08 | 945 | 1733 | Low-fire glaze, bisque for low-fire clay | long |
| 06 | 991 | 1816 | Common low-fire glaze | long |
| 05 | 1031 | 1888 | Low-fire glaze, some bisque | typical |
| 04 | 1063 | 1945 | Standard bisque firing | typical |
| 03 | 1086 | 1987 | Earthenware glaze | typical |
| 02 | 1102 | 2016 | Earthenware glaze | typical |
| 01 | 1119 | 2046 | Earthenware glaze | typical |
| 1 | 1137 | 2079 | Mid-range, some stoneware | typical |
| 2 | 1142 | 2088 | Mid-range | typical |
| 3 | 1152 | 2106 | Mid-range stoneware | typical |
| 4 | 1162 | 2124 | Mid-range stoneware | shorter |
| 5 | 1186 | 2167 | Mid-range stoneware and porcelain | shorter |
| 6 | 1222 | 2232 | The most common studio glaze firing | shorter |
| 7 | 1239 | 2262 | Stoneware | short |
| 8 | 1249 | 2280 | Stoneware | short |
| 9 | 1260 | 2300 | Stoneware, porcelain | short |
| 10 | 1285 | 2345 | High-fire stoneware and porcelain | shortest |
| 11 | 1294 | 2361 | High-fire | shortest |
| 12 | 1306 | 2383 | High-fire | shortest |
What the element-life column means. Wear is driven by peak temperature far more than by hours at moderate heat, so the same kiln gets through sets much faster at cone 10 than at cone 04. Treat it as relative, not a countdown — and if your kiln disagrees with this table, your witness cone is right. More on when to replace a set.
Cone and firing questions
Why do published cone temperatures differ between charts?
Because a cone measures heat work, not temperature — the combination of how hot and for how long. Orton publishes separate tables for different ramp rates, and the same cone bends around 10 °C lower on a slow climb than a fast one. This table uses 60 °C per hour, which is close to what most studio controllers do over the final stretch. Treat any table as a guide and the witness cone in your own kiln as the answer.
How much does firing one cone higher really cost in element life?
More than most people expect, because element wear is driven by peak temperature rather than hours. Moving a regular schedule from cone 6 to cone 10 can roughly halve the number of firings you get from a set. If you fire high routinely, treat elements as a running cost and budget for them rather than being surprised.
My kiln reaches temperature but the cone does not bend properly.
That usually means the controller is reading a temperature the chamber is not actually holding — often an ageing thermocouple, sometimes elements that can no longer sustain the top of the ramp. If firings have also been getting longer, suspect the elements. A resistance reading will tell you which it is.
Does firing to a lower cone let old elements keep working?
Often, yes, for a while. Elements that can no longer hold cone 6 may still reach cone 04 reliably, so a set that has aged out of glaze work can sometimes finish its life doing bisque. It is a reprieve rather than a fix, and it only works if your schedule genuinely allows the lower range.
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Firing hot and getting through sets quickly?
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