Crane main performance parameters indicators: starting weight. Total lifting weight: from the total weight of the crane can lift the material along with the spreader and can be divided into long-term fixed on the crane spreader and drama (including hooks, pulley blocks, hoisting rope and the crane trolley following other lifting objects ) The total mass. Crane main performance parameters indicators: effective starting weight. Used crane 25 tons crane spreader with separable (eg grab, electromagnetic sucker, balance beam, etc.), the spreader and the material quality of the overall service the rated capacity, allowing liter from quality material is effective from the weight. Lifting height: Lifting height is the crane orbit top surface (or floor) to the vertical distance from the extract means extreme position, the unit is m.