
26
CONE
LARGE CONES
NUMBER
60 DEG. C. 106 DEG. F.
O22
576 C.
1069 F.
O21
602
1116
O20
625
1157
O19
668
1234
O18
696
1285
O17
727
1341
O16
764
1407
O15
790
1454
O14
834
1533
O13
869
1596
O12
866
1591
O11
886
1627
O10
897
1629
O9
915
1679
O8
945
1733
O7
973
1783
O6
991
1816
O5
1031
1888
O4
1050
1922
O3
1086
1987
O2
1101
2014
O1
1117
2043
1
1136
2077
2
1142
2088
3
1152
2106
4
1168
2134
5
1177
2151
6
1201
2194
7
1215
2219
8
1236
2257
10
2350
SOAKING
- Heat treating objects in a kiln by keeping them at a particular temperature for a period of time.
STILTS
- Small ceramic or high temperature metal prongs used to raise a piece off the kiln shelf. Used chiefly in glaze firings
to prevent sticking to the kiln or shelf. Many styles are available.
STONEWARE
- A ceramic body which is vitreous but not translucent when high fired. It usually contains a high percentage
of grog (fired clay particles) and is usually made of native clays.
TERRA COTTA
- A natural, low fire red clay.
THERMAL SHOCK
- the result of putting ware through sudden changes in temperature.
THERMOCOUPLE
- Two wires of different metals which are inserted into the kiln and comprise the temperature sensing
part of the pyrometer. It produces a very small voltage in proportion to the difference in temperature between the tip (hot
junction) of the thermocouple inside the hot kiln and the cold junction on the outside of the kiln.
UNDERGLAZE
- Decorative material applied to greenware or bisque.
VENTING
- Allowing air into the kiln and vapors to escape by propping the lid slightly open and sometimes opening the
peepholes. Usually done only in the early stages of firing.
VITRIFY
- To fully fuse ceramic material to a glass-like state so that it is nonporous and watertight without glazing.
WARE
- General term for any shaped ceramic object whether or not it is in a finished state.
WARPAGE
- Deformation of ware during firing, usually due to overfiring or to improper placement in the kiln.