The 6400 Straight Thread Connector is one of our most popular hydraulic fittings. The 6400 is commonly used to connect flared hydraulic tubing or a JIC female hose end to an SAE straight thread port, common on many pumps and cylinders. Suitable for a wide range of fluids, type 316 stainless steel provides maximum corrosion-resistance. Nominal sizes are shown below. See our size chart for actual thread dimensions.