How is the "standard bucket capacity" of an excavator determined?

The standard bucket capacity refers to the heaped capacity of a bucket that represents the excavator’s class when excavating soil with a bulk density of 1800 kg/m³. In China, the bucket capacity of hydraulic excavators is determined in accordance with the provisions of GB3225-1982 Calibration of Hydraulic Excavator Bucket Capacity. It is the sum of the flat-filled bucket capacity (calculated based on the inner dimensions of the bucket) and the volume of the heaped portion. The boundary between the flat-filled bucket capacity and the heaped portion is called the calibration surface.

Does the "maximum rated lifting capacity" of a crane change under different working conditions?

Yes, it does. The maximum rated lifting capacity refers to the maximum mass of a load that the crane can safely lift under specified basic boom length and minimum working radius. However, in actual operations, as the boom length increases and the working radius expands, the crane’s maximum rated lifting capacity gradually decreases. This is because changes in boom length and working radius affect the crane’s stability and force-bearing conditions.