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