Cone 9 temperature
Orton cone 9 bends at 2300 °F (1260 °C) at 108 °F/hr and 2336 °F (1280 °C) at 270 °F/hr. It sits in the high fire range — cone 33 of 38 on the chart, counting up from 022.
108 °F/hr · 60 °C/hr
2300 °F1260 °C
Medium — the rate most charts quote
270 °F/hr · 150 °C/hr
2336 °F1280 °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 2300 °F is not the same as firing to cone 9 — put a witness cone on the shelf.
Cone 9 is not cone 09
Cone 09 — with the leading zero — is 612 °F cooler (1688 °F), in the low fire range. Read the zero as “oh”; a glaze labeled for one will not behave at the other.
What cone 9 is used for
High fire — Traditional stoneware and porcelain, especially in gas reduction. Cone 10 is the classic high-fire target; cone 9–10 is where shinos, celadons, and copper reds live.
Cone 9 compared
| Comparison | At 108 °F/hr | Difference (medium) | Difference (fast) | |
|---|---|---|---|---|
| cone 9 vs cone 09 | 1688 → 2300 °F | 612 °F (340 °C) | 630 °F (350 °C) | cone 9 is hotter |
| cone 9 vs cone 8 | 2280 → 2300 °F | 20 °F (11 °C) | 16 °F (9 °C) | cone 9 is hotter |
| cone 9 vs cone 10 | 2300 → 2345 °F | 45 °F (25 °C) | 45 °F (25 °C) | cone 10 is hotter |
| cone 9 vs cone 06 | 1828 → 2300 °F | 472 °F (262 °C) | 481 °F (267 °C) | cone 9 is hotter |
| cone 9 vs cone 04 | 1945 → 2300 °F | 355 °F (197 °C) | 365 °F (203 °C) | cone 9 is hotter |
| cone 9 vs cone 5 | 2167 → 2300 °F | 133 °F (74 °C) | 131 °F (73 °C) | cone 9 is hotter |
| cone 9 vs cone 6 | 2232 → 2300 °F | 68 °F (38 °C) | 67 °F (37 °C) | cone 9 is hotter |
Convert
cone 9 bends at
2300 °F(1260 °C)
At 108 °F/hr (60 °C/hr) — medium. Faster firing → the same cone bends hotter. Everything about cone 9 →
Questions
- What temperature is cone 9?
- Orton cone 9 bends at about 2300 °F (1260 °C) when the kiln climbs at 108 °F per hour, and about 2336 °F (1280 °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 9 in Celsius?
- 1260 °C at 108 °F/hr (60 °C/hr) and 1280 °C at 270 °F/hr (150 °C/hr), converted from Orton's Fahrenheit chart for self-supporting regular cones.
- Is cone 9 the same as cone 09?
- 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 9 used for?
- cone 9 sits in the high fire range. Traditional stoneware and porcelain, especially in gas reduction. Cone 10 is the classic high-fire target; cone 9–10 is where shinos, celadons, and copper reds live.
- How far is cone 9 from cone 8 and cone 10?
- At 108 °F/hr, cone 8 bends 20 °F cooler (2280 °F) and cone 10 bends 45 °F hotter (2345 °F). One cone step is not a fixed number of degrees — the spacing varies across the chart.
Firing to cone 9? Claybench schedules the kiln around it.
Clay body, glazes, and firing schedule are matched by cone before a plan is saved.