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Cone 4 temperature

Orton cone 4 bends at 2124 °F (1162 °C) at 108 °F/hr and 2161 °F (1183 °C) at 270 °F/hr. It sits in the between the ranges range — cone 27 of 38 on the chart, counting up from 022.

108 °F/hr · 60 °C/hr

2124 °F1162 °C

Medium — the rate most charts quote

270 °F/hr · 150 °C/hr

2161 °F1183 °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 2124 °F is not the same as firing to cone 4 — put a witness cone on the shelf.

Cone 4 is not cone 04

Cone 04 — with the leading zero — is 179 °F cooler (1945 °F), in the bisque & earthenware range. Read the zero as “oh”; a glaze labeled for one will not behave at the other.

What cone 4 is used for

Between the ranges — Upper earthenware and lower mid-range. Less common as a target than the cones either side; some commercial glazes and sculpture bodies specify it.

Cone 4 compared

ComparisonAt 108 °F/hrDifference (medium)Difference (fast)
cone 4 vs cone 0419452124 °F179 °F (99 °C)190 °F (106 °C)cone 4 is hotter
cone 4 vs cone 321062124 °F18 °F (10 °C)23 °F (13 °C)cone 4 is hotter
cone 4 vs cone 521242167 °F43 °F (24 °C)44 °F (24 °C)cone 5 is hotter
cone 4 vs cone 0618282124 °F296 °F (164 °C)306 °F (170 °C)cone 4 is hotter
cone 4 vs cone 621242232 °F108 °F (60 °C)108 °F (60 °C)cone 6 is hotter
cone 4 vs cone 1021242345 °F221 °F (123 °C)220 °F (122 °C)cone 10 is hotter

Neighboring cones

ConeMedium °F / °CFast °F / °CRange
cone 5½2197 / 12032237 / 1225Mid fire
cone 52167 / 11862205 / 1207Mid fire
cone 42124 / 11622161 / 1183Between the ranges
cone 32106 / 11522138 / 1170Between the ranges
cone 22088 / 11422127 / 1164Between the ranges

Convert

cone 4 bends at

2124 °F(1162 °C)

At 108 °F/hr (60 °C/hr) — medium. Faster firing → the same cone bends hotter. Everything about cone 4 →

Questions

What temperature is cone 4?
Orton cone 4 bends at about 2124 °F (1162 °C) when the kiln climbs at 108 °F per hour, and about 2161 °F (1183 °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 4 in Celsius?
1162 °C at 108 °F/hr (60 °C/hr) and 1183 °C at 270 °F/hr (150 °C/hr), converted from Orton's Fahrenheit chart for self-supporting regular cones.
Is cone 4 the same as cone 04?
No — and this is the most common cone mix-up. Cones with a leading zero count down toward cone 1, so cone 04 is cooler than cone 4: about 1945 °F versus 2124 °F at 108 °F/hr, a difference of 179 °F. Read the zero as "oh", not as nothing.
What is cone 4 used for?
cone 4 sits in the between the ranges range. Upper earthenware and lower mid-range. Less common as a target than the cones either side; some commercial glazes and sculpture bodies specify it.
How far is cone 4 from cone 3 and cone 5?
At 108 °F/hr, cone 3 bends 18 °F cooler (2106 °F) and cone 5 bends 43 °F hotter (2167 °F). One cone step is not a fixed number of degrees — the spacing varies across the chart.

Firing to cone 4? Claybench schedules the kiln around it.

Clay body, glazes, and firing schedule are matched by cone before a plan is saved.

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