Below is a list of Hydro Cutting manufacturers from Napa, California. Hydro cutting is a cold working manufacturing process that uses high pressure water jets to cut a wide variety of materials and shape them into many designs. Flat or semi-flat materials like metal, glass, plastic, foam, marble, stone and wood are cut using either pure water or, in the case of abrasive water jet cutting, water mixed with abrasive particles like garnet or diamond for added strength; abrasive media are usually added for use on tougher materials.