Steel Heating and Tempering Colours Page

The charts below are from one large fold out chart. That is why the word "temperature" is broken in two parts.

Here is the ASSAB intro for the chart.

"As every heat treater knows, each tool steel grade has its own specific hardening and tempering temperatures. It is important to use the correct temperature when heat treating the steel. And there is no substitute for good instrumentation and temperature control. However, the colour charts in this folder have proved a popular supplement to the pyrometer, to quickly get a rough estimate of the temperature."

Note how you should view the steel for these temperatures above.


Please note, although the colours here are very similar to the original chart on my computer/display set-up they may (probably) be different on other displays. At least those unfamiliar with the colour changes will still get an idea as to how they change and the order of the changes. The charts are based on Celcius temp scale.

Heat affected steel shavings. Also known as swarf, and various other names preceeded with plenty of expletives if you get one inside your shirt etc.


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