The definition of a hydraulic adapter is a fitting designed to connect different types of hose, tubing, or pipe together. Below is a Thread Identification Chart that will help to identify which type of thread or flange connection you are working with and which type of thread or flange connection you need to get to. Feel free to print this chart and use it as a reference when attempting to identify a certain thread or flange type, then call us at one of our locations to place an order for your hydraulic adapter.