The metal hose mainly refers to a spiral bellows; the other is a ring bellows.
The spiral bellows is a tubular shell in which the corrugations are arranged in a spiral shape. There is a spiral angle between adjacent corrugations, and all the corrugations can be connected by a spiral.
The annular bellows is a tubular shell with a corrugated closed annular shape, and the wave and the wave are formed by a series of annular corrugations. The annular bellows are formed from seamless tubing or welded tubing. Constrained by the processing method, the length of a single tube is usually shorter than that of a spiral bellows. The advantages of the annular bellows are good elasticity and low rigidity.