Is hydraulic oil thicker 32 or 68?
Mia Phillips
Updated on May 03, 2026
32 is thinner, No. 46 is medium and No. 68 is thicker. Generally speaking, if the temperature is low in winter, use #32 & #46 hydraulic oil with a lower viscosity, and use #68 hydraulic oil with a higher viscosity in summer.
What is the difference between ISO 32 and ISO 68?
Viscosity gradesISO grades measure viscosity at 104°F(40°C). When you look at, for instance, ISO 32 hydraulic oil it will flow much more quickly than ISO 68 hydraulic oil. Different viscosities are better for different applications in the field.