Below is a list of Hydrolic Cylinders manufacturers from Grand Rapids, Michigan. Hydrolic, or hydraulic cylinders, are devices used to convert pressurized fluid into mechanical power in the form of linear force or movement. A simple device, hydraulic cylinders are usually made up of two main parts: an outer cylinder barrel containing hydraulic fluid, and a hydraulic piston which is connected to a rod which moves it up and down inside the barrel. The distance that a piston travels with the cylinder until it is fully extended is known as its stroke. The length of a stroke is often used to classify the cylinder and this length can range widely from less than an inch to several feet in length in relation to the power required.