Heat Treat Colors for Steel

The chart shows the heat treat colors for steel by temperature.

 

The above chart shows the heat treat colors for steel by temperature.

These days, pyrometers are affordable, but it is the mark of a craftsman to be able to tell temperature by eye, if only to validate the instrumentation or suspect it.

These colors were obtained from a 0.40 wt. percent carbon, alloy steel, as seen through a furnace peep hole during average daylight conditions.

All Craftsman’s Cribsheets are available for viewing and download at short.productionmachining.com/cribsheets.