Cone 09 temperature
Orton cone 09 bends at 1688 °F (920 °C) at 108 °F/hr and 1706 °F (930 °C) at 270 °F/hr. It sits in the low fire range — cone 14 of 38 on the chart, counting up from 022.
108 °F/hr · 60 °C/hr
1688 °F920 °C
Medium — the rate most charts quote
270 °F/hr · 150 °C/hr
1706 °F930 °C
Fast — typical of a quick electric firing
Orton self-supporting regular cones; rate measured over the last 200 °F of the firing. Source: Orton °F chart; °C converted. Cones measure heat-work, so a controller set to 1688 °F is not the same as firing to cone 09 — put a witness cone on the shelf.
Cone 09 is not cone 9
The leading zero means cone 09 counts down from cone 1 — it's a low fire temperature (1688 °F). Cone 9 is 612 °F hotter (2300 °F), in the high fire range.
What cone 09 is used for
Low fire — Below the usual bisque range. Some low-fire glazes, glass, and enamel work land here; cone 010–08 appears as a soft bisque for very porous ware.
Cone 09 compared
| Comparison | At 108 °F/hr | Difference (medium) | Difference (fast) | |
|---|---|---|---|---|
| cone 09 vs cone 9 | 1688 → 2300 °F | 612 °F (340 °C) | 630 °F (350 °C) | cone 9 is hotter |
| cone 09 vs cone 010 | 1657 → 1688 °F | 31 °F (17 °C) | 27 °F (15 °C) | cone 09 is hotter |
| cone 09 vs cone 08 | 1688 → 1728 °F | 40 °F (22 °C) | 47 °F (26 °C) | cone 08 is hotter |
| cone 09 vs cone 06 | 1688 → 1828 °F | 140 °F (78 °C) | 149 °F (83 °C) | cone 06 is hotter |
| cone 09 vs cone 04 | 1688 → 1945 °F | 257 °F (143 °C) | 265 °F (147 °C) | cone 04 is hotter |
| cone 09 vs cone 5 | 1688 → 2167 °F | 479 °F (266 °C) | 499 °F (277 °C) | cone 5 is hotter |
| cone 09 vs cone 6 | 1688 → 2232 °F | 544 °F (302 °C) | 563 °F (313 °C) | cone 6 is hotter |
| cone 09 vs cone 10 | 1688 → 2345 °F | 657 °F (365 °C) | 675 °F (375 °C) | cone 10 is hotter |
Convert
cone 09 bends at
1688 °F(920 °C)
At 108 °F/hr (60 °C/hr) — medium. Faster firing → the same cone bends hotter. Everything about cone 09 →
Questions
- What temperature is cone 09?
- Orton cone 09 bends at about 1688 °F (920 °C) when the kiln climbs at 108 °F per hour, and about 1706 °F (930 °C) at 270 °F per hour. Cones measure heat-work — temperature over time — so the faster you fire, the hotter the kiln has to get for the same cone to bend.
- What is cone 09 in Celsius?
- 920 °C at 108 °F/hr (60 °C/hr) and 930 °C at 270 °F/hr (150 °C/hr), converted from Orton's Fahrenheit chart for self-supporting regular cones.
- Is cone 09 the same as cone 9?
- No — and this is the most common cone mix-up. Cones with a leading zero count down toward cone 1, so cone 09 is cooler than cone 9: about 1688 °F versus 2300 °F at 108 °F/hr, a difference of 612 °F. Read the zero as "oh", not as nothing.
- What is cone 09 used for?
- cone 09 sits in the low fire range. Below the usual bisque range. Some low-fire glazes, glass, and enamel work land here; cone 010–08 appears as a soft bisque for very porous ware.
- How far is cone 09 from cone 010 and cone 08?
- At 108 °F/hr, cone 010 bends 31 °F cooler (1657 °F) and cone 08 bends 40 °F hotter (1728 °F). One cone step is not a fixed number of degrees — the spacing varies across the chart.
Firing to cone 09? Claybench schedules the kiln around it.
Clay body, glazes, and firing schedule are matched by cone before a plan is saved.