Ceramic Cones: What They Measure in Pottery
Ceramic cones are small heat indicators used in kilns to show how much heatwork a firing has received. They matter because kiln temperature alone does not tell the full story; time and heat together affect how clay and glaze mature.
That is why potters often trust cones as a real-world check on whether a firing reached the result they wanted.
Why cones matter
- They show whether the kiln delivered the right amount of heatwork.
- They help confirm if a glaze or clay body reached maturity.
- They reveal whether a kiln fired hotter or cooler than expected in a specific spot.
How cone numbers work
Low-fire ranges often use cones like 06 to 01, mid-range usually falls around cone 4 to 6, and higher-fire work can go to cone 10 and beyond. The important thing is not just the number but whether the cone bends as expected during the firing.
Cones are especially useful when you want to compare glaze results, learn your kiln’s behavior, or troubleshoot inconsistent firings.