Cone Firing Numbers

In standard firing, cones of the right number are placed around the kiln and are watched. When the cones fall the kiln is turned off. This works the same for gas and electric kilns.
Automatic electric kilns such as the Skutt Kilnmaster series have a thermocouple which continuously measures the temperature, records it over time, and shuts off when the appropriate heat absorption has been met. So if the ramping temperature is fast, the kiln will go to a higher temperature before it turns off than if the ramping temperature is slow (thus allowing the clay to absorb more heat along the way.) The final temperature is most affected by the rate of temperature increase over the last 300 to 400 degrees of firing.

Think of the 0 in a cone number as meaning "minus". So 06 is much cooler than 6 because it is like a "minus 6".


Cone /Orton Cones / Orton Cones /Orton Cones
number /Final temp in / Final temp in /Final temp
/ /degrees F at / degrees F at /in degrees F at
/ /ramp rate of / ramp rate of / ramp rate of
/ /27 degrees F/hr /108 degrees F/hr /270 degrees F/hr

10 /2284 / 2345 / 2381
9 / 2235 / 2300 / 2336
8 /2212 /2273 /2320
7 /2194 /2262 /2295
6 /2165 /2232 /2269
5 /2118 /2167 /2205
4 /2086 /2142 /2161
3 /2039 /2106 /2138
2 /2034 /2088 /2127
1 /2028 /2079 /2109
01 /1999/ 2046/ 2080
02 /1972/ 2016/ 2052
03 /1960/ 1987/ 2019
04 /1915/ 1945/ 1971
05 /1870/ 1888/ 1911
06 /1798/ 1828/ 1855
07 /1764/ 1789/ 1809
08 /1692/ 1728/ 1753
09 /1665/ 1688/ 1706
010 /1636 /1657/ 1679
011 /1575 /1607/ 1641
012 /1549 /1582/ 1620
013 /1485 /1539/ 1582
014 /1395 /1485 /1540
015 /1382 /1456 /1504
016 /1368 /1422 /1465
017 /1301 /1360 /1405
018 /1267 /1252 /1283
019 /1213 /1252 /1283
020 / /1159/ 1180
021 / / 1112/ 1143
022 / /1087/ 1094

Temperature conversion

Temperature conversions between the three temperature scales:

kelvin / degree Celsius conversions (exact):

kelvins = degrees Celsius + 273.15
degrees Celsius = kelvins - 273.15


degree Fahrenheit / degree Celsius conversions (exact):

degrees F = (degrees C x 9/5)+ 32
degrees C = (degrees F - 32) x 5/9

or
go to Convertor
http://chemistry.about.com/library/weekly/bltempconvert.htm