The working level of a crane is divided according to its frequency of use and load status, which is an important parameter for evaluating crane design and selection. The ISO 4301-1 standard is generally used internationally to define the working level of a crane, which divides cranes into 8 working levels:
| A1-A2 | Light working level | Suitable for cranes with low frequency of use and light loads, such as maintenance workshops or cranes used occasionally. |
| A3-A4 | Medium working level | Suitable for cranes with medium frequency of use and loads, such as cranes in machining workshops or assembly lines. |
| A5-A6 | Heavy working level | Suitable for cranes with high frequency of use and loads, such as cranes in steel mills, ports or heavy manufacturing industries. |
| A7-A8 | Extra heavy working level | Suitable for cranes with extremely high frequency of use and loads, such as foundries with continuous operation or cranes in large ports. |
Each working level has its corresponding definition of load status and frequency of use. Load status is usually divided into light load, medium load, heavy load and extra heavy load, while the frequency of use reflects the number of times the crane is operated within a certain period of time (usually one year).
When selecting a crane, it is crucial to understand the required working level because it directly affects the crane's design, material selection, structural strength and maintenance requirements. Improper selection of working level may cause the crane to be damaged prematurely or unable to meet work needs, thus affecting production efficiency and safety.
