hydraulic press, device consisting of a cylinder fitted with a sliding piston that exerts force upon a confined liquid, which, in turn, produces a compressive force upon a stationary anvil or baseplate. The liquid is forced into the cylinder by a pump. The hydraulic press is widely used in industry for forming metals and for other tasks where a large force is required. It is manufactured in a wide variety of styles and sizes and in capacities ranging from 1 ton or less to 10,000 tons or more.