Judging the quality of a gas spring is mainly considered from the following aspects: first, its sealing performance, if the sealing performance is not good, oil and air leakage will occur during use; the second is accuracy, such as 500N. For gas springs, the force error produced by some manufacturers does not exceed 2N, and the products of some manufacturers may be far from the actual 500N required; again, the service life is calculated by the number of times that it can be fully retracted; the last is The force value changes during the stroke, and the gas spring in an ideal state should maintain the same force value throughout the stroke. However, due to design and processing factors, the force value of the gas spring in the stroke inevitably changes. The magnitude of its change is an important criterion for measuring the quality of a gas spring. The smaller the magnitude of the change, the better the quality of the gas spring, and vice versa!