1. First of all, material identification. The materials of round steel rods are different and can be distinguished by material identification. Ordinary carbon steel round rods can be identified as C45 and S45C, and alloy steel round rods can be identified as 42CrMo4.

2. Secondly, the specifications are marked. The specifications of round steel bars are also different, and they can be distinguished by the specification marks. A round steel bar with a diameter of 10mm can be marked as 10mm, and a round steel bar with a diameter of 20mm can be marked as 20mm.

3. Finally, the brand logo. The round steel rods provided by different suppliers have different brands, which can be distinguished by the brand logo. The round steel bars provided by a certain supplier are branded as "Mashan Iron and Steel" and can be identified as "Mashan Iron and Steel" round steel bars. It can complete different types of marking operations for different suppliers of round steel bars.