Steel has different colors at different temperatures. For ease of identification, the colors of steel at different temperatures have been compared and summarized for practical use.
The heating color in the rectangular box refers to the color of the heating steel bar as seen through the observation hole of the furnace under normal fluorescent room temperature illumination conditions of approximately 500 lux.
Relationship between fire color and temperature in steel heating
| Fire color | Temperature (℃) |
| Dark brown | 520——580 |
| Dark red | 580—650 |
| Dark cherry | 650—750 |
| Cherry red | 750—780 |
| Light cherry red | 780—800 |
| Light red | 800—830 |
| Orange yellow reddish | 830—850 |
| Pale color | 880—1050 |
| Yellow | 1050—1150 |
| Canary yellow | 1150—1250 |
| Yellowish white | 1250—1300 |
| Bright white | 1300—1350 |
