ISO VG 46 hydraulic oil is a lubricant that meets the physical properties outlined by the International Standards Organization's requirements for viscosity grade 46. The number 46 refers to the oil's kinematic viscosity in centistrokes at 40 degrees Celsius, with a 10 percent margin of tolerance allowed.
Hydraulic oil is different than other lubricants because it must perform two tasks. It must be able to meet lubrication responsibilities similar to other oils, but hydraulic oil also works as a tool to transfer power.
To be an effective lubricant, it must maintain many standard oil properties, including foaming resistance and air release; thermal, oxidation and hydrolytic stability; anti-wear performance; filterability and demulsibility. It must also inhibit rust and corrosion, while maintaining a similar viscosity in relation to film thickness.
To function properly as a power transfer tool, it must maintain a high resistance to volume reduction under pressure, and maintain a high viscosity index that inhibits viscosity change through a wide range of operating temperatures.
ISO VG 46 hydraulic oils are widely used, and very flexible for a wide range of applications and equipment. Most major oil products manufacturers market a brand of ISO VG 46 equivalent hydraulic oil, including Mobile DTE 25, Shell Tellus S2 M 46, Sunoco SUNVIS 46, Coastal Premium AW 46 and Phillips Conoco 76 Megaflow AW 46.